nested namepace and related cleanup

72 files changed, 629 insertions, 831 deletions

diff --git a/searchlib/src/vespa/searchlib/features/agefeature.h b/searchlib/src/vespa/searchlib/features/agefeature.h
index 99898af910f..2914d2df472 100644
--- a/searchlib/src/vespa/searchlib/features/agefeature.h
+++ b/searchlib/src/vespa/searchlib/features/agefeature.h
@@ -2,11 +2,9 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchcommon/attribute/attributecontent.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the documentage feature outputting the
@@ -42,5 +40,3 @@ public:
 };
 
 }
-}
-
diff --git a/searchlib/src/vespa/searchlib/features/attributefeature.h b/searchlib/src/vespa/searchlib/features/attributefeature.h
index 2d206fb738e..c115c4acaea 100644
--- a/searchlib/src/vespa/searchlib/features/attributefeature.h
+++ b/searchlib/src/vespa/searchlib/features/attributefeature.h
@@ -3,11 +3,9 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/eval/eval/value_type.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the blueprint for the attribute executor.
@@ -32,6 +30,4 @@ public:
     bool setup(const fef::IIndexEnvironment & env, const fef::ParameterList & params) override;
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/attributematchfeature.h b/searchlib/src/vespa/searchlib/features/attributematchfeature.h
index 3cdc6e322a3..487a35ab573 100644
--- a/searchlib/src/vespa/searchlib/features/attributematchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/attributematchfeature.h
@@ -2,13 +2,10 @@
 
 #pragma once
 
-#include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 #include "queryterm.h"
+#include <vespa/searchlib/fef/blueprint.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 struct AttributeMatchParams {
     AttributeMatchParams() :
@@ -74,7 +71,7 @@ private:
 
     Computer _cmp;
 
-    virtual void handle_bind_match_data(const fef::MatchData &md) override;
+    void handle_bind_match_data(const fef::MatchData &md) override;
 
 public:
     /**
@@ -106,7 +103,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/closenessfeature.h b/searchlib/src/vespa/searchlib/features/closenessfeature.h
index 15e9bf574f1..d5e3cb36505 100644
--- a/searchlib/src/vespa/searchlib/features/closenessfeature.h
+++ b/searchlib/src/vespa/searchlib/features/closenessfeature.h
@@ -4,10 +4,8 @@
 
 #include "logarithmcalculator.h"
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the closeness feature.
@@ -44,6 +42,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/constant_feature.h b/searchlib/src/vespa/searchlib/features/constant_feature.h
index 8f0e2f1cf8e..b7e4a9fdcab 100644
--- a/searchlib/src/vespa/searchlib/features/constant_feature.h
+++ b/searchlib/src/vespa/searchlib/features/constant_feature.h
@@ -6,8 +6,7 @@
 
 namespace vespalib { namespace eval { struct ConstantValue; } }
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the blueprint for the constant feature.
@@ -15,7 +14,7 @@ namespace features {
  * An executor of this outputs the value of a named constant.
  * This can either be a number or a tensor value.
  */
-class ConstantBlueprint : public search::fef::Blueprint {
+class ConstantBlueprint : public fef::Blueprint {
 private:
     vespalib::string _key;  // 'foo'
     std::unique_ptr<vespalib::eval::ConstantValue> _value;
@@ -26,23 +25,19 @@ public:
      */
     ConstantBlueprint();
 
-    ~ConstantBlueprint();
+    ~ConstantBlueprint() override;
 
-    virtual void visitDumpFeatures(const search::fef::IIndexEnvironment &env,
-                                   search::fef::IDumpFeatureVisitor &visitor) const override;
+    void visitDumpFeatures(const fef::IIndexEnvironment &env, fef::IDumpFeatureVisitor &visitor) const override;
 
-    virtual search::fef::Blueprint::UP createInstance() const override;
+    fef::Blueprint::UP createInstance() const override;
 
-    virtual search::fef::ParameterDescriptions getDescriptions() const override {
-        return search::fef::ParameterDescriptions().desc().string();
+    fef::ParameterDescriptions getDescriptions() const override {
+        return fef::ParameterDescriptions().desc().string();
     }
 
-    virtual bool setup(const search::fef::IIndexEnvironment &env,
-                       const search::fef::ParameterList &params) override;
+    bool setup(const fef::IIndexEnvironment &env, const fef::ParameterList &params) override;
 
-    virtual search::fef::FeatureExecutor &createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
+    fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/constant_tensor_executor.h b/searchlib/src/vespa/searchlib/features/constant_tensor_executor.h
index 43ce48282ee..2ab7b98fabe 100644
--- a/searchlib/src/vespa/searchlib/features/constant_tensor_executor.h
+++ b/searchlib/src/vespa/searchlib/features/constant_tensor_executor.h
@@ -9,8 +9,7 @@
 #include <vespa/eval/tensor/default_tensor_engine.h>
 #include <memory>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Feature executor that returns a constant tensor.
@@ -24,8 +23,8 @@ public:
     ConstantTensorExecutor(vespalib::eval::Value::UP tensor)
         : _tensor(std::move(tensor))
     {}
-    virtual bool isPure() override { return true; }
-    virtual void execute(uint32_t) override {
+    bool isPure() override { return true; }
+    void execute(uint32_t) override {
         outputs().set_object(0, *_tensor);
     }
     static fef::FeatureExecutor &create(std::unique_ptr<vespalib::eval::Tensor> tensor, vespalib::Stash &stash) {
@@ -41,5 +40,4 @@ public:
     }
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/debug_attribute_wait.h b/searchlib/src/vespa/searchlib/features/debug_attribute_wait.h
index fdb23a3f374..94083448ce9 100644
--- a/searchlib/src/vespa/searchlib/features/debug_attribute_wait.h
+++ b/searchlib/src/vespa/searchlib/features/debug_attribute_wait.h
@@ -2,13 +2,10 @@
 
 #pragma once
 
-#include <string>
-#include <vector>
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/searchcommon/attribute/attributecontent.h>
-#include <vespa/searchlib/fef/fef.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
@@ -33,8 +30,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-//-----------------------------------------------------------------------------
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/debug_wait.h b/searchlib/src/vespa/searchlib/features/debug_wait.h
index 881cf6cf289..f185b5fae1b 100644
--- a/searchlib/src/vespa/searchlib/features/debug_wait.h
+++ b/searchlib/src/vespa/searchlib/features/debug_wait.h
@@ -2,12 +2,9 @@
 
 #pragma once
 
-#include <string>
-#include <vector>
-#include <vespa/searchlib/fef/fef.h>
+#include <vespa/searchlib/fef/blueprint.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
@@ -35,8 +32,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-//-----------------------------------------------------------------------------
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/dense_tensor_attribute_executor.h b/searchlib/src/vespa/searchlib/features/dense_tensor_attribute_executor.h
index 3b66d3d0ba1..2bcf356689e 100644
--- a/searchlib/src/vespa/searchlib/features/dense_tensor_attribute_executor.h
+++ b/searchlib/src/vespa/searchlib/features/dense_tensor_attribute_executor.h
@@ -6,9 +6,8 @@
 #include <vespa/eval/eval/value.h>
 #include <vespa/eval/tensor/dense/mutable_dense_tensor_view.h>
 
-namespace search {
-namespace tensor { class ITensorAttribute; }
-namespace features {
+namespace search::tensor { class ITensorAttribute; }
+namespace search::features {
 
 /**
  * Executor for extracting dense tensors from an underlying dense tensor attribute
@@ -25,5 +24,4 @@ public:
     void execute(uint32_t docId) override;
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/distancefeature.h b/searchlib/src/vespa/searchlib/features/distancefeature.h
index eaa3c3e50f6..3c75d53ad77 100644
--- a/searchlib/src/vespa/searchlib/features/distancefeature.h
+++ b/searchlib/src/vespa/searchlib/features/distancefeature.h
@@ -2,13 +2,10 @@
 
 #pragma once
 
-#include <vespa/searchcommon/attribute/attributecontent.h>
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
+#include <vespa/searchcommon/attribute/attributecontent.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the distance feature.
@@ -54,7 +51,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/distancetopathfeature.h b/searchlib/src/vespa/searchlib/features/distancetopathfeature.h
index 442f1ba3b28..e36ace0c601 100644
--- a/searchlib/src/vespa/searchlib/features/distancetopathfeature.h
+++ b/searchlib/src/vespa/searchlib/features/distancetopathfeature.h
@@ -1,10 +1,8 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 #pragma once
 
-#include <vespa/searchcommon/attribute/attributecontent.h>
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
+#include <vespa/searchcommon/attribute/attributecontent.h>
 
 namespace search::features {
 
diff --git a/searchlib/src/vespa/searchlib/features/documenttestutils.cpp b/searchlib/src/vespa/searchlib/features/documenttestutils.cpp
index 896e0922a48..e13699576cd 100644
--- a/searchlib/src/vespa/searchlib/features/documenttestutils.cpp
+++ b/searchlib/src/vespa/searchlib/features/documenttestutils.cpp
@@ -16,9 +16,7 @@
 LOG_SETUP(".features.utils");
 using namespace search::fef;
 
-namespace search {
-namespace features {
-namespace util {
+namespace search::features::util {
 
 feature_t lookupConnectedness(const search::fef::IQueryEnvironment & env, uint32_t termId, feature_t fallback)
 {
@@ -152,6 +150,4 @@ getTermByLabel(const search::fef::IQueryEnvironment &env, const vespalib::string
     return 0;
 }
 
-} // namespace util
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/dotproductfeature.cpp b/searchlib/src/vespa/searchlib/features/dotproductfeature.cpp
index 0173455bcf9..ae1271edf5d 100644
--- a/searchlib/src/vespa/searchlib/features/dotproductfeature.cpp
+++ b/searchlib/src/vespa/searchlib/features/dotproductfeature.cpp
@@ -64,9 +64,9 @@ DotProductExecutor<Vector, Buffer>::execute(uint32_t docId)
     outputs().set_number(0, val);
 }
 
-StringVector::StringVector() { }
+StringVector::StringVector() = default;
 
-StringVector::~StringVector() { }
+StringVector::~StringVector() = default;
 
 }
 
@@ -81,7 +81,7 @@ DotProductExecutorBase<BaseType>::DotProductExecutorBase(const V & queryVector)
 }
 
 template <typename BaseType>
-DotProductExecutorBase<BaseType>::~DotProductExecutorBase() { }
+DotProductExecutorBase<BaseType>::~DotProductExecutorBase() = default;
 
 template <typename BaseType>
 void DotProductExecutorBase<BaseType>::execute(uint32_t docId) {
diff --git a/searchlib/src/vespa/searchlib/features/dotproductfeature.h b/searchlib/src/vespa/searchlib/features/dotproductfeature.h
index c350494db0e..9356fe9c7f2 100644
--- a/searchlib/src/vespa/searchlib/features/dotproductfeature.h
+++ b/searchlib/src/vespa/searchlib/features/dotproductfeature.h
@@ -4,18 +4,14 @@
 
 #include "utils.h"
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/attribute/multivalue.h>
 #include <vespa/vespalib/hwaccelrated/iaccelrated.h>
 #include <vespa/searchcommon/attribute/attributecontent.h>
 #include <vespa/vespalib/stllike/hash_map.hpp>
 
-namespace search {
-namespace fef {
-class Property;
-}
+namespace search::fef { class Property; }
 
-namespace features {
+namespace search::features {
 
 namespace dotproduct {
 
@@ -246,7 +242,7 @@ public:
     SparseDotProductByContentFillExecutor(const attribute::IAttributeVector * attribute,
                                           const V & queryVector,
                                           const IV & queryIndexes);
-    ~SparseDotProductByContentFillExecutor();
+    ~SparseDotProductByContentFillExecutor() override;
 private:
     size_t getAttributeValues(uint32_t docid, const AT * & values) final override;
 
@@ -259,7 +255,6 @@ private:
 
 }
 
-
 /**
  * Implements the blueprint for the foreach executor.
  */
@@ -272,7 +267,7 @@ private:
 
 public:
     DotProductBlueprint();
-    ~DotProductBlueprint();
+    ~DotProductBlueprint() override;
     void visitDumpFeatures(const fef::IIndexEnvironment & env, fef::IDumpFeatureVisitor & visitor) const override;
     fef::Blueprint::UP createInstance() const override;
 
@@ -281,10 +276,6 @@ public:
     bool setup(const fef::IIndexEnvironment & env, const fef::ParameterList & params) override;
     void prepareSharedState(const fef::IQueryEnvironment & queryEnv, fef::IObjectStore & objectStore) const override;
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
-
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/element_completeness_feature.cpp b/searchlib/src/vespa/searchlib/features/element_completeness_feature.cpp
index 18988281cbd..1d71fa9d47c 100644
--- a/searchlib/src/vespa/searchlib/features/element_completeness_feature.cpp
+++ b/searchlib/src/vespa/searchlib/features/element_completeness_feature.cpp
@@ -1,13 +1,16 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "element_completeness_feature.h"
+#include <vespa/searchlib/fef/itermdata.h>
+#include <vespa/searchlib/fef/featurenamebuilder.h>
+#include <vespa/searchlib/fef/properties.h>
 #include <vespa/vespalib/locale/c.h>
 
 namespace search::features {
 
 //-----------------------------------------------------------------------------
 
-ElementCompletenessExecutor::ElementCompletenessExecutor(const search::fef::IQueryEnvironment &env,
+ElementCompletenessExecutor::ElementCompletenessExecutor(const fef::IQueryEnvironment &env,
                                                          const ElementCompletenessParams &params)
     : _params(params),
       _terms(),
@@ -16,11 +19,11 @@ ElementCompletenessExecutor::ElementCompletenessExecutor(const search::fef::IQue
       _md(nullptr)
 {
     for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
-        const search::fef::ITermData *termData = env.getTerm(i);
+        const fef::ITermData *termData = env.getTerm(i);
         if (termData->getWeight().percent() != 0) { // only consider query terms with contribution
-            typedef search::fef::ITermFieldRangeAdapter FRA;
+            typedef fef::ITermFieldRangeAdapter FRA;
             for (FRA iter(*termData); iter.valid(); iter.next()) {
-                const search::fef::ITermFieldData &tfd = iter.get();
+                const fef::ITermFieldData &tfd = iter.get();
                 if (tfd.getFieldId() == _params.fieldId) {
                     int termWeight = termData->getWeight().percent();
                     _sumTermWeight += termWeight;
@@ -36,7 +39,7 @@ ElementCompletenessExecutor::execute(uint32_t docId)
 {
     assert(_queue.empty());
     for (size_t i = 0; i < _terms.size(); ++i) {
-        const search::fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms[i].termHandle);
+        const fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms[i].termHandle);
         if (tfmd->getDocId() == docId) {
             Item item(i, tfmd->begin(), tfmd->end());
             if (item.pos != item.end) {
@@ -92,14 +95,14 @@ ElementCompletenessBlueprint::ElementCompletenessBlueprint()
 }
 
 void
-ElementCompletenessBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironment &env,
-                                                search::fef::IDumpFeatureVisitor &visitor) const
+ElementCompletenessBlueprint::visitDumpFeatures(const fef::IIndexEnvironment &env,
+                                                fef::IDumpFeatureVisitor &visitor) const
 {
     for (uint32_t i = 0; i < env.getNumFields(); ++i) {
-        const search::fef::FieldInfo &field = *env.getField(i);
-        if (field.type() == search::fef::FieldType::INDEX) {
+        const fef::FieldInfo &field = *env.getField(i);
+        if (field.type() == fef::FieldType::INDEX) {
             if (!field.isFilter()) {
-                search::fef::FeatureNameBuilder fnb;
+                fef::FeatureNameBuilder fnb;
                 fnb.baseName(getBaseName()).parameter(field.name());
                 for (size_t out = 0; out < _output.size(); ++out) {
                     visitor.visitDumpFeature(fnb.output(_output[out]).buildName());
@@ -109,21 +112,21 @@ ElementCompletenessBlueprint::visitDumpFeatures(const search::fef::IIndexEnviron
     }
 }
 
-search::fef::Blueprint::UP
+fef::Blueprint::UP
 ElementCompletenessBlueprint::createInstance() const
 {
     return Blueprint::UP(new ElementCompletenessBlueprint());
 }
 
 bool
-ElementCompletenessBlueprint::setup(const search::fef::IIndexEnvironment &env,
-                                    const search::fef::ParameterList &params)
+ElementCompletenessBlueprint::setup(const fef::IIndexEnvironment &env,
+                                    const fef::ParameterList &params)
 {
-    const search::fef::FieldInfo *field = params[0].asField();
+    const fef::FieldInfo *field = params[0].asField();
 
     _params.fieldId = field->id();
-    const search::fef::Properties &lst = env.getProperties();
-    search::fef::Property obj = lst.lookup(getName(), "fieldCompletenessImportance");
+    const fef::Properties &lst = env.getProperties();
+    fef::Property obj = lst.lookup(getName(), "fieldCompletenessImportance");
     if (obj.found()) {
         _params.fieldCompletenessImportance = vespalib::locale::c::atof(obj.get().c_str());
     }
@@ -135,8 +138,8 @@ ElementCompletenessBlueprint::setup(const search::fef::IIndexEnvironment &env,
     return true;
 }
 
-search::fef::FeatureExecutor &
-ElementCompletenessBlueprint::createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const
+fef::FeatureExecutor &
+ElementCompletenessBlueprint::createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const
 {
     return stash.create<ElementCompletenessExecutor>(env, _params);
 }
diff --git a/searchlib/src/vespa/searchlib/features/element_completeness_feature.h b/searchlib/src/vespa/searchlib/features/element_completeness_feature.h
index 1b835da45d2..ea971b6b036 100644
--- a/searchlib/src/vespa/searchlib/features/element_completeness_feature.h
+++ b/searchlib/src/vespa/searchlib/features/element_completeness_feature.h
@@ -2,11 +2,10 @@
 
 #pragma once
 
-#include <vespa/searchlib/fef/fef.h>
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/vespalib/util/priority_queue.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
@@ -117,8 +116,4 @@ public:
     const ElementCompletenessParams &getParams() const { return _params; }
 };
 
-//-----------------------------------------------------------------------------
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/element_similarity_feature.cpp b/searchlib/src/vespa/searchlib/features/element_similarity_feature.cpp
index c9eab238f82..73d3262ab4e 100644
--- a/searchlib/src/vespa/searchlib/features/element_similarity_feature.cpp
+++ b/searchlib/src/vespa/searchlib/features/element_similarity_feature.cpp
@@ -1,430 +1,464 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "element_similarity_feature.h"
+#include <vespa/searchlib/fef/itermdata.h>
+#include <vespa/searchlib/fef/featurenamebuilder.h>
+#include <vespa/searchlib/fef/properties.h>
 #include <vespa/eval/eval/llvm/compiled_function.h>
 #include <vespa/eval/eval/llvm/compile_cache.h>
 
 #include <vespa/log/log.h>
 LOG_SETUP(".features.elementsimilarity");
 
-namespace search {
+namespace search::features {
 
-using CollectionType = fef::FieldInfo::CollectionType;
+    using CollectionType = fef::FieldInfo::CollectionType;
 
-namespace features {
-
-namespace {
+    namespace {
 
 //-----------------------------------------------------------------------------
 
-struct Aggregator {
-    typedef std::unique_ptr<Aggregator> UP;
-    virtual UP create() const = 0;
-    virtual void clear() = 0;
-    virtual void add(double) = 0;
-    virtual double get() const = 0;
-    virtual ~Aggregator() {}
-};
-
-struct MaxAggregator : Aggregator {
-    size_t count;
-    double value;
-    MaxAggregator() : count(0), value(0.0) {}
-    UP create() const override { return UP(new MaxAggregator()); }
-    void clear() override { count = 0; value = 0.0; }
-    void add(double v) override { value = ((++count == 1) || (v > value)) ? v : value; }
-    double get() const override { return value; }
-};
-
-struct AvgAggregator : Aggregator {
-    size_t count;
-    double value;
-    AvgAggregator() : count(0), value(0.0) {}
-    UP create() const override { return UP(new AvgAggregator()); }
-    void clear() override { count = 0; value = 0.0; }
-    void add(double v) override { ++count; value += v; }
-    double get() const override { return (count == 0) ? 0.0 : (value/count); }
-};
-
-struct SumAggregator : Aggregator {
-    double value;
-    SumAggregator() : value(0.0) {}
-    UP create() const override { return UP(new SumAggregator()); }
-    void clear() override { value = 0.0; }
-    void add(double v) override { value += v; }
-    double get() const override { return value; }
-};
-
-Aggregator::UP create_aggregator(const vespalib::string &name) {
-    if (name == "max") {
-        return Aggregator::UP(new MaxAggregator());
-    }
-    if (name == "avg") {
-        return Aggregator::UP(new AvgAggregator());
-    }
-    if (name == "sum") {
-        return Aggregator::UP(new SumAggregator());
-    }
-    return Aggregator::UP(nullptr);
-}
+        struct Aggregator {
+            typedef std::unique_ptr<Aggregator> UP;
 
-//-----------------------------------------------------------------------------
+            virtual UP create() const = 0;
+
+            virtual void clear() = 0;
+
+            virtual void add(double) = 0;
+
+            virtual double get() const = 0;
+
+            virtual ~Aggregator() {}
+        };
+
+        struct MaxAggregator : Aggregator {
+            size_t count;
+            double value;
+
+            MaxAggregator() : count(0), value(0.0) {}
+
+            UP create() const override { return UP(new MaxAggregator()); }
+
+            void clear() override {
+                count = 0;
+                value = 0.0;
+            }
+
+            void add(double v) override { value = ((++count == 1) || (v > value)) ? v : value; }
+
+            double get() const override { return value; }
+        };
+
+        struct AvgAggregator : Aggregator {
+            size_t count;
+            double value;
+
+            AvgAggregator() : count(0), value(0.0) {}
+
+            UP create() const override { return UP(new AvgAggregator()); }
+
+            void clear() override {
+                count = 0;
+                value = 0.0;
+            }
+
+            void add(double v) override {
+                ++count;
+                value += v;
+            }
+
+            double get() const override { return (count == 0) ? 0.0 : (value / count); }
+        };
+
+        struct SumAggregator : Aggregator {
+            double value;
 
-typedef double (*function_5)(double, double, double, double, double);
-typedef std::pair<function_5, Aggregator::UP> OutputSpec;
+            SumAggregator() : value(0.0) {}
+
+            UP create() const override { return UP(new SumAggregator()); }
+
+            void clear() override { value = 0.0; }
+
+            void add(double v) override { value += v; }
+
+            double get() const override { return value; }
+        };
+
+        Aggregator::UP create_aggregator(const vespalib::string &name) {
+            if (name == "max") {
+                return Aggregator::UP(new MaxAggregator());
+            }
+            if (name == "avg") {
+                return Aggregator::UP(new AvgAggregator());
+            }
+            if (name == "sum") {
+                return Aggregator::UP(new SumAggregator());
+            }
+            return Aggregator::UP(nullptr);
+        }
 
 //-----------------------------------------------------------------------------
 
-struct VectorizedQueryTerms {
-    struct Term {
-        fef::TermFieldHandle handle;
-        int                          weight;
-        int                          index;
-        Term(fef::TermFieldHandle handle_in, int weight_in, int index_in)
-            : handle(handle_in), weight(weight_in), index(index_in) {}
-    };
+        typedef double (*function_5)(double, double, double, double, double);
+
+        typedef std::pair<function_5, Aggregator::UP> OutputSpec;
+
+//-----------------------------------------------------------------------------
 
-    std::vector<fef::TermFieldHandle> handles;
-    std::vector<int>                  weights;
-    int                               total_weight;
-
-    VectorizedQueryTerms(const VectorizedQueryTerms &) = delete;
-    VectorizedQueryTerms(VectorizedQueryTerms &&rhs)
-        : handles(std::move(rhs.handles)), weights(std::move(rhs.weights)), total_weight(rhs.total_weight) {}
-    VectorizedQueryTerms(const fef::IQueryEnvironment &env, uint32_t field_id)
-        : handles(), weights(), total_weight(0)
-    {
-        std::vector<Term> terms;
-        for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
-            const fef::ITermData *termData = env.getTerm(i);
-            if (termData->getWeight().percent() != 0) { // only consider query terms with contribution
-                typedef fef::ITermFieldRangeAdapter FRA;
-                for (FRA iter(*termData); iter.valid(); iter.next()) {
-                    const fef::ITermFieldData &tfd = iter.get();
-                    if (tfd.getFieldId() == field_id) {
-                        int term_weight = termData->getWeight().percent();
-                        total_weight += term_weight;
-                        terms.push_back(Term(tfd.getHandle(), term_weight,
-                                        termData->getTermIndex()));
+        struct VectorizedQueryTerms {
+            struct Term {
+                fef::TermFieldHandle handle;
+                int weight;
+                int index;
+
+                Term(fef::TermFieldHandle handle_in, int weight_in, int index_in)
+                        : handle(handle_in), weight(weight_in), index(index_in) {}
+            };
+
+            std::vector<fef::TermFieldHandle> handles;
+            std::vector<int> weights;
+            int total_weight;
+
+            VectorizedQueryTerms(const VectorizedQueryTerms &) = delete;
+
+            VectorizedQueryTerms(VectorizedQueryTerms &&rhs)
+                    : handles(std::move(rhs.handles)), weights(std::move(rhs.weights)),
+                      total_weight(rhs.total_weight) {}
+
+            VectorizedQueryTerms(const fef::IQueryEnvironment &env, uint32_t field_id)
+                    : handles(), weights(), total_weight(0) {
+                std::vector<Term> terms;
+                for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
+                    const fef::ITermData *termData = env.getTerm(i);
+                    if (termData->getWeight().percent() != 0) { // only consider query terms with contribution
+                        typedef fef::ITermFieldRangeAdapter FRA;
+                        for (FRA iter(*termData); iter.valid(); iter.next()) {
+                            const fef::ITermFieldData &tfd = iter.get();
+                            if (tfd.getFieldId() == field_id) {
+                                int term_weight = termData->getWeight().percent();
+                                total_weight += term_weight;
+                                terms.push_back(Term(tfd.getHandle(), term_weight,
+                                                     termData->getTermIndex()));
+                            }
+                        }
                     }
                 }
+                std::sort(terms.begin(), terms.end(), [](const Term &a, const Term &b) { return (a.index < b.index); });
+                handles.reserve(terms.size());
+                weights.reserve(terms.size());
+                for (size_t i = 0; i < terms.size(); ++i) {
+                    handles.push_back(terms[i].handle);
+                    weights.push_back(terms[i].weight);
+                }
             }
-        }
-        std::sort(terms.begin(), terms.end(), [](const Term &a, const Term &b){ return (a.index < b.index); });
-        handles.reserve(terms.size());
-        weights.reserve(terms.size());
-        for (size_t i = 0; i < terms.size(); ++i) {
-            handles.push_back(terms[i].handle);
-            weights.push_back(terms[i].weight);
-        }
-    }
-    ~VectorizedQueryTerms();
-};
 
-VectorizedQueryTerms::~VectorizedQueryTerms() { }
+            ~VectorizedQueryTerms();
+        };
+
+        VectorizedQueryTerms::~VectorizedQueryTerms() {}
 
 //-----------------------------------------------------------------------------
 
-struct State {
-    uint32_t  element_length;
-    uint32_t  matched_terms;
-    int       sum_term_weight;
-    uint32_t  last_pos;
-    double    sum_proximity_score;
-    uint32_t  last_idx;
-    uint32_t  num_in_order;
-
-    double proximity;
-    double order;
-    double query_coverage;
-    double field_coverage;
-    double element_weight;
-
-    State(uint32_t element_length_in, int32_t element_weight_in,
-          uint32_t first_pos, int32_t first_weight, uint32_t first_idx)
-        : element_length(element_length_in),
-          matched_terms(1), sum_term_weight(first_weight),
-          last_pos(first_pos), sum_proximity_score(0.0),
-          last_idx(first_idx), num_in_order(0),
-          proximity(0.0), order(0.0),
-          query_coverage(0.0), field_coverage(0.0),
-          element_weight(element_weight_in) {}
-
-    double proximity_score(uint32_t dist) {
-        return (dist > 8) ? 0 : (1.0 - (((dist-1)/8.0) * ((dist-1)/8.0)));
-    }
+        struct State {
+            uint32_t element_length;
+            uint32_t matched_terms;
+            int sum_term_weight;
+            uint32_t last_pos;
+            double sum_proximity_score;
+            uint32_t last_idx;
+            uint32_t num_in_order;
+
+            double proximity;
+            double order;
+            double query_coverage;
+            double field_coverage;
+            double element_weight;
+
+            State(uint32_t element_length_in, int32_t element_weight_in,
+                  uint32_t first_pos, int32_t first_weight, uint32_t first_idx)
+                    : element_length(element_length_in),
+                      matched_terms(1), sum_term_weight(first_weight),
+                      last_pos(first_pos), sum_proximity_score(0.0),
+                      last_idx(first_idx), num_in_order(0),
+                      proximity(0.0), order(0.0),
+                      query_coverage(0.0), field_coverage(0.0),
+                      element_weight(element_weight_in) {}
+
+            double proximity_score(uint32_t dist) {
+                return (dist > 8) ? 0 : (1.0 - (((dist - 1) / 8.0) * ((dist - 1) / 8.0)));
+            }
 
-    bool want_match(uint32_t pos) {
-        return (pos > last_pos);
-    }
+            bool want_match(uint32_t pos) {
+                return (pos > last_pos);
+            }
 
-    void addMatch(uint32_t pos, int32_t weight, uint32_t idx) {
-        sum_proximity_score += proximity_score(pos - last_pos);
-        num_in_order += (idx > last_idx) ? 1 : 0;
-        last_pos = pos;
-        last_idx = idx;        
-        ++matched_terms;
-        sum_term_weight += weight;
-    }
+            void addMatch(uint32_t pos, int32_t weight, uint32_t idx) {
+                sum_proximity_score += proximity_score(pos - last_pos);
+                num_in_order += (idx > last_idx) ? 1 : 0;
+                last_pos = pos;
+                last_idx = idx;
+                ++matched_terms;
+                sum_term_weight += weight;
+            }
 
-    void calculate_scores(size_t num_query_terms, int total_term_weight) {
-        double matches = std::min(element_length, matched_terms);
-        if (matches < 2) {
-            proximity = proximity_score(element_length);
-            order = (num_query_terms == 1) ? 1.0 : 0.0;
-        } else {
-            proximity = sum_proximity_score / (matches - 1);
-            order = num_in_order / (double) (matches - 1);
-        }
-        query_coverage = sum_term_weight / (double) total_term_weight;
-        field_coverage = matches / (double) element_length;
-    }
-};
+            void calculate_scores(size_t num_query_terms, int total_term_weight) {
+                double matches = std::min(element_length, matched_terms);
+                if (matches < 2) {
+                    proximity = proximity_score(element_length);
+                    order = (num_query_terms == 1) ? 1.0 : 0.0;
+                } else {
+                    proximity = sum_proximity_score / (matches - 1);
+                    order = num_in_order / (double) (matches - 1);
+                }
+                query_coverage = sum_term_weight / (double) total_term_weight;
+                field_coverage = matches / (double) element_length;
+            }
+        };
 
 //-----------------------------------------------------------------------------
 
-class ElementSimilarityExecutor : public fef::FeatureExecutor
-{
-private:
-    typedef fef::TermFieldMatchData::PositionsIterator ITR;
-
-    struct CmpPosition {
-        ITR *pos;
-        CmpPosition(ITR *pos_in) : pos(pos_in) {}
-        bool operator()(uint16_t a, uint16_t b) {
-            return (pos[a]->getPosition() == pos[b]->getPosition())
-                ? (a < b)
-                : (pos[a]->getPosition() < pos[b]->getPosition());
-        }
-    };
+        class ElementSimilarityExecutor : public fef::FeatureExecutor {
+        private:
+            typedef fef::TermFieldMatchData::PositionsIterator ITR;
 
-    struct CmpElement {
-        ITR *pos;
-        CmpElement(ITR *pos_in) : pos(pos_in) {}
-        bool operator()(uint16_t a, uint16_t b) {
-            return pos[a]->getElementId() < pos[b]->getElementId();
-        }
-    };
+            struct CmpPosition {
+                ITR *pos;
 
-    typedef vespalib::PriorityQueue<uint16_t, CmpPosition> PositionQueue;
-    typedef vespalib::PriorityQueue<uint16_t, CmpElement>  ElementQueue;
-
-    VectorizedQueryTerms    _terms;
-    std::vector<ITR>        _pos;
-    std::vector<ITR>        _end;
-    PositionQueue           _position_queue;
-    ElementQueue            _element_queue;
-    std::vector<OutputSpec> _outputs;
-    const fef::MatchData *_md;
-
-public:
-    ElementSimilarityExecutor(VectorizedQueryTerms &&terms, std::vector<OutputSpec> &&outputs_in)
-        : _terms(std::move(terms)),
-          _pos(_terms.handles.size(), nullptr),
-          _end(_terms.handles.size(), nullptr),
-          _position_queue(CmpPosition(&_pos[0])),
-          _element_queue(CmpElement(&_pos[0])),
-          _outputs(std::move(outputs_in)),
-          _md(nullptr)
-    {}
-
-    bool isPure() override { return _terms.handles.empty(); }
-
-    void handle_bind_match_data(const fef::MatchData &md) override {
-        _md = &md;
-    }
+                CmpPosition(ITR *pos_in) : pos(pos_in) {}
 
-    void requeue_term(uint16_t term, uint32_t element) {
-        while (_pos[term] != _end[term] &&
-               _pos[term]->getElementId() == element)
-        {
-            ++_pos[term];
-        }
-        if (_pos[term] != _end[term]) {
-            _element_queue.push(term);
-        }
-    }
+                bool operator()(uint16_t a, uint16_t b) {
+                    return (pos[a]->getPosition() == pos[b]->getPosition())
+                           ? (a < b)
+                           : (pos[a]->getPosition() < pos[b]->getPosition());
+                }
+            };
 
-    void execute(uint32_t docId) override {
-        for (auto &output: _outputs) {
-            output.second->clear();
-        }
-        for (size_t i = 0; i < _terms.handles.size(); ++i) {
-            const fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms.handles[i]);
-            if (tfmd->getDocId() == docId) {
-                _pos[i] = tfmd->begin();
-                _end[i] = tfmd->end();
-                if (_pos[i] != _end[i]) {
-                    _element_queue.push(i);
+            struct CmpElement {
+                ITR *pos;
+
+                CmpElement(ITR *pos_in) : pos(pos_in) {}
+
+                bool operator()(uint16_t a, uint16_t b) {
+                    return pos[a]->getElementId() < pos[b]->getElementId();
                 }
+            };
+
+            typedef vespalib::PriorityQueue<uint16_t, CmpPosition> PositionQueue;
+            typedef vespalib::PriorityQueue<uint16_t, CmpElement> ElementQueue;
+
+            VectorizedQueryTerms _terms;
+            std::vector<ITR> _pos;
+            std::vector<ITR> _end;
+            PositionQueue _position_queue;
+            ElementQueue _element_queue;
+            std::vector<OutputSpec> _outputs;
+            const fef::MatchData *_md;
+
+        public:
+            ElementSimilarityExecutor(VectorizedQueryTerms &&terms, std::vector<OutputSpec> &&outputs_in)
+                    : _terms(std::move(terms)),
+                      _pos(_terms.handles.size(), nullptr),
+                      _end(_terms.handles.size(), nullptr),
+                      _position_queue(CmpPosition(&_pos[0])),
+                      _element_queue(CmpElement(&_pos[0])),
+                      _outputs(std::move(outputs_in)),
+                      _md(nullptr) {}
+
+            bool isPure() override { return _terms.handles.empty(); }
+
+            void handle_bind_match_data(const fef::MatchData &md) override {
+                _md = &md;
             }
-        }
-        while (!_element_queue.empty()) {
-            uint32_t elementId = _pos[_element_queue.front()]->getElementId();
-            while (!_element_queue.empty() && _pos[_element_queue.front()]->getElementId() == elementId) {
-                _position_queue.push(_element_queue.front());
-                _element_queue.pop_front();
+
+            void requeue_term(uint16_t term, uint32_t element) {
+                while (_pos[term] != _end[term] &&
+                       _pos[term]->getElementId() == element) {
+                    ++_pos[term];
+                }
+                if (_pos[term] != _end[term]) {
+                    _element_queue.push(term);
+                }
             }
-            uint16_t first = _position_queue.front();
-            State state(_pos[first]->getElementLen(),
-                        _pos[first]->getElementWeight(),
-                        _pos[first]->getPosition(),
-                        _terms.weights[first],
-                        first);
-            requeue_term(_position_queue.front(), elementId);
-            _position_queue.pop_front();
-            while (!_position_queue.empty()) {
-                uint16_t item = _position_queue.front();
-                if (state.want_match(_pos[item]->getPosition())) {
-                    state.addMatch(_pos[item]->getPosition(),
-                                   _terms.weights[item],
-                                   item);
-                    requeue_term(_position_queue.front(), elementId);                    
+
+            void execute(uint32_t docId) override {
+                for (auto &output: _outputs) {
+                    output.second->clear();
+                }
+                for (size_t i = 0; i < _terms.handles.size(); ++i) {
+                    const fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms.handles[i]);
+                    if (tfmd->getDocId() == docId) {
+                        _pos[i] = tfmd->begin();
+                        _end[i] = tfmd->end();
+                        if (_pos[i] != _end[i]) {
+                            _element_queue.push(i);
+                        }
+                    }
+                }
+                while (!_element_queue.empty()) {
+                    uint32_t elementId = _pos[_element_queue.front()]->getElementId();
+                    while (!_element_queue.empty() && _pos[_element_queue.front()]->getElementId() == elementId) {
+                        _position_queue.push(_element_queue.front());
+                        _element_queue.pop_front();
+                    }
+                    uint16_t first = _position_queue.front();
+                    State state(_pos[first]->getElementLen(),
+                                _pos[first]->getElementWeight(),
+                                _pos[first]->getPosition(),
+                                _terms.weights[first],
+                                first);
+                    requeue_term(_position_queue.front(), elementId);
                     _position_queue.pop_front();
-                } else {
-                    ++_pos[item];
-                    if (_pos[item] == _end[item]) {
-                        _position_queue.pop_front();
-                    } else {
-                        _position_queue.adjust();
+                    while (!_position_queue.empty()) {
+                        uint16_t item = _position_queue.front();
+                        if (state.want_match(_pos[item]->getPosition())) {
+                            state.addMatch(_pos[item]->getPosition(),
+                                           _terms.weights[item],
+                                           item);
+                            requeue_term(_position_queue.front(), elementId);
+                            _position_queue.pop_front();
+                        } else {
+                            ++_pos[item];
+                            if (_pos[item] == _end[item]) {
+                                _position_queue.pop_front();
+                            } else {
+                                _position_queue.adjust();
+                            }
+                        }
+                    }
+                    state.calculate_scores(_terms.handles.size(), _terms.total_weight);
+                    for (auto &output: _outputs) {
+                        output.second->add(output.first(state.proximity, state.order,
+                                                        state.query_coverage, state.field_coverage,
+                                                        state.element_weight));
                     }
                 }
+                for (size_t i = 0; i < _outputs.size(); ++i) {
+                    outputs().set_number(i, _outputs[i].second->get());
+                }
             }
-            state.calculate_scores(_terms.handles.size(), _terms.total_weight);
-            for (auto &output: _outputs) {
-                output.second->add(output.first(state.proximity, state.order,
-                                state.query_coverage, state.field_coverage,
-                                state.element_weight));
-            }
-        }
-        for (size_t i = 0; i < _outputs.size(); ++i) {
-            outputs().set_number(i, _outputs[i].second->get());
-        }
-    }
-};
+        };
 
 //-----------------------------------------------------------------------------
 
-std::vector<std::pair<vespalib::string, vespalib::string> > extract_properties(const fef::Properties &props,
-        const vespalib::string &ns, const vespalib::string &first_name, const vespalib::string &first_default)
-{
-    struct MyVisitor : fef::IPropertiesVisitor {
-        const vespalib::string &first_name;
-        std::vector<std::pair<vespalib::string, vespalib::string> > &result;
-        MyVisitor(const vespalib::string &first_name_in,
-                  std::vector<std::pair<vespalib::string, vespalib::string> > &result_in)
-            : first_name(first_name_in), result(result_in) {}
-        virtual void visitProperty(const fef::Property::Value &key,
-                                   const fef::Property &values) override
-        {
-            if (key != first_name) {
-                result.emplace_back(key, values.get());
-            }
+        std::vector<std::pair<vespalib::string, vespalib::string> > extract_properties(const fef::Properties &props,
+                                                                                       const vespalib::string &ns,
+                                                                                       const vespalib::string &first_name,
+                                                                                       const vespalib::string &first_default) {
+            struct MyVisitor : fef::IPropertiesVisitor {
+                const vespalib::string &first_name;
+                std::vector<std::pair<vespalib::string, vespalib::string> > &result;
+
+                MyVisitor(const vespalib::string &first_name_in,
+                          std::vector<std::pair<vespalib::string, vespalib::string> > &result_in)
+                        : first_name(first_name_in), result(result_in) {}
+
+                virtual void visitProperty(const fef::Property::Value &key,
+                                           const fef::Property &values) override {
+                    if (key != first_name) {
+                        result.emplace_back(key, values.get());
+                    }
+                }
+            };
+            std::vector<std::pair<vespalib::string, vespalib::string> > result;
+            result.emplace_back(first_name, props.lookup(ns, first_name).get(first_default));
+            MyVisitor my_visitor(first_name, result);
+            props.visitNamespace(ns, my_visitor);
+            return result;
         }
-    };
-    std::vector<std::pair<vespalib::string, vespalib::string> > result;
-    result.emplace_back(first_name, props.lookup(ns, first_name).get(first_default));
-    MyVisitor my_visitor(first_name, result);
-    props.visitNamespace(ns, my_visitor);
-    return result;
-}
 
-std::vector<std::pair<vespalib::string, vespalib::string> > get_outputs(const fef::Properties &props,
-        const vespalib::string &feature)
-{
-    return extract_properties(props, feature + ".output", "default", "max((0.35*p+0.15*o+0.30*q+0.20*f)*w)");
-}
+        std::vector<std::pair<vespalib::string, vespalib::string> > get_outputs(const fef::Properties &props,
+                                                                                const vespalib::string &feature) {
+            return extract_properties(props, feature + ".output", "default", "max((0.35*p+0.15*o+0.30*q+0.20*f)*w)");
+        }
 
-} // namespace features::<unnamed>
+    } // namespace features::<unnamed>
 
 //-----------------------------------------------------------------------------
 
-struct ElementSimilarityBlueprint::OutputContext {
-    vespalib::eval::CompileCache::Token::UP compile_token;    
-    Aggregator::UP aggregator_factory;
-    OutputContext(const vespalib::eval::Function &function,
-                  Aggregator::UP aggregator)
-        : compile_token(vespalib::eval::CompileCache::compile(function, vespalib::eval::PassParams::SEPARATE)),
-          aggregator_factory(std::move(aggregator)) {}
-};
+    struct ElementSimilarityBlueprint::OutputContext {
+        vespalib::eval::CompileCache::Token::UP compile_token;
+        Aggregator::UP aggregator_factory;
+
+        OutputContext(const vespalib::eval::Function &function,
+                      Aggregator::UP aggregator)
+                : compile_token(vespalib::eval::CompileCache::compile(function, vespalib::eval::PassParams::SEPARATE)),
+                  aggregator_factory(std::move(aggregator)) {}
+    };
 
 //-----------------------------------------------------------------------------
 
-ElementSimilarityBlueprint::ElementSimilarityBlueprint()
-    : Blueprint("elementSimilarity"), _field_id(fef::IllegalHandle), _outputs() {}
-
-ElementSimilarityBlueprint::~ElementSimilarityBlueprint() {}
-
-void
-ElementSimilarityBlueprint::visitDumpFeatures(const fef::IIndexEnvironment &env,
-                                              fef::IDumpFeatureVisitor &visitor) const
-{
-    for (uint32_t i = 0; i < env.getNumFields(); ++i) {
-        const fef::FieldInfo &field = *env.getField(i);
-        if ((field.type() == fef::FieldType::INDEX) &&
-            (field.collection() != CollectionType::SINGLE) &&
-            ( ! field.isFilter()))
-        {
-            fef::FeatureNameBuilder fnb;
-            fnb.baseName(getBaseName()).parameter(field.name());
-            auto outputs = get_outputs(env.getProperties(), fnb.buildName());
-            visitor.visitDumpFeature(fnb.output("").buildName());
-            for (size_t out_idx = 1; out_idx < outputs.size(); ++out_idx) {
-                visitor.visitDumpFeature(fnb.output(outputs[out_idx].first).buildName());
+    ElementSimilarityBlueprint::ElementSimilarityBlueprint()
+            : Blueprint("elementSimilarity"), _field_id(fef::IllegalHandle), _outputs() {}
+
+    ElementSimilarityBlueprint::~ElementSimilarityBlueprint() {}
+
+    void
+    ElementSimilarityBlueprint::visitDumpFeatures(const fef::IIndexEnvironment &env,
+                                                  fef::IDumpFeatureVisitor &visitor) const {
+        for (uint32_t i = 0; i < env.getNumFields(); ++i) {
+            const fef::FieldInfo &field = *env.getField(i);
+            if ((field.type() == fef::FieldType::INDEX) &&
+                (field.collection() != CollectionType::SINGLE) &&
+                (!field.isFilter())) {
+                fef::FeatureNameBuilder fnb;
+                fnb.baseName(getBaseName()).parameter(field.name());
+                auto outputs = get_outputs(env.getProperties(), fnb.buildName());
+                visitor.visitDumpFeature(fnb.output("").buildName());
+                for (size_t out_idx = 1; out_idx < outputs.size(); ++out_idx) {
+                    visitor.visitDumpFeature(fnb.output(outputs[out_idx].first).buildName());
+                }
             }
         }
     }
-}
 
-bool
-ElementSimilarityBlueprint::setup(const fef::IIndexEnvironment &env,
-                                  const fef::ParameterList &params)
-{
-    const fef::FieldInfo *field = params[0].asField();
-    _field_id = field->id();
-    fef::FeatureNameBuilder fnb;
-    fnb.baseName(getBaseName()).parameter(field->name());
-    auto outputs = get_outputs(env.getProperties(), fnb.buildName());
-    for (const auto &entry: outputs) {
-        describeOutput(entry.first, entry.second);
-        vespalib::string aggr_name;
-        vespalib::string expr;
-        vespalib::string error;
-        if (!vespalib::eval::Function::unwrap(entry.second, aggr_name, expr, error)) {
-            LOG(warning, "'%s': could not extract aggregator and expression for output '%s' from config value '%s' (%s)",
-                fnb.buildName().c_str(), entry.first.c_str(), entry.second.c_str(), error.c_str());
-            return false;
-        }
-        Aggregator::UP aggr = create_aggregator(aggr_name);
-        if (aggr.get() == nullptr) {
-            LOG(warning, "'%s': unknown aggregator '%s'", fnb.buildName().c_str(), aggr_name.c_str());
-            return false;
-        }
-        std::vector<vespalib::string> args({"p","o","q","f","w"});
-        vespalib::eval::Function function = vespalib::eval::Function::parse(args, expr);
-        if (function.has_error()) {
-            LOG(warning, "'%s': per-element expression parse error: %s",
-                fnb.buildName().c_str(), function.get_error().c_str());
-            return false;
+    bool
+    ElementSimilarityBlueprint::setup(const fef::IIndexEnvironment &env,
+                                      const fef::ParameterList &params) {
+        const fef::FieldInfo *field = params[0].asField();
+        _field_id = field->id();
+        fef::FeatureNameBuilder fnb;
+        fnb.baseName(getBaseName()).parameter(field->name());
+        auto outputs = get_outputs(env.getProperties(), fnb.buildName());
+        for (const auto &entry: outputs) {
+            describeOutput(entry.first, entry.second);
+            vespalib::string aggr_name;
+            vespalib::string expr;
+            vespalib::string error;
+            if (!vespalib::eval::Function::unwrap(entry.second, aggr_name, expr, error)) {
+                LOG(warning,
+                    "'%s': could not extract aggregator and expression for output '%s' from config value '%s' (%s)",
+                    fnb.buildName().c_str(), entry.first.c_str(), entry.second.c_str(), error.c_str());
+                return false;
+            }
+            Aggregator::UP aggr = create_aggregator(aggr_name);
+            if (aggr.get() == nullptr) {
+                LOG(warning, "'%s': unknown aggregator '%s'", fnb.buildName().c_str(), aggr_name.c_str());
+                return false;
+            }
+            std::vector<vespalib::string> args({"p", "o", "q", "f", "w"});
+            vespalib::eval::Function function = vespalib::eval::Function::parse(args, expr);
+            if (function.has_error()) {
+                LOG(warning, "'%s': per-element expression parse error: %s",
+                    fnb.buildName().c_str(), function.get_error().c_str());
+                return false;
+            }
+            _outputs.push_back(OutputContext_UP(new OutputContext(function, std::move(aggr))));
         }
-        _outputs.push_back(OutputContext_UP(new OutputContext(function, std::move(aggr))));
+        env.hintFieldAccess(field->id());
+        return true;
     }
-    env.hintFieldAccess(field->id());
-    return true;
-}
 
-fef::FeatureExecutor &
-ElementSimilarityBlueprint::createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const
-{
-    std::vector<OutputSpec> output_specs;
-    for (const auto &output: _outputs) {
-        output_specs.emplace_back(output->compile_token->get().get_function<5>(),
-                                  output->aggregator_factory->create());
+    fef::FeatureExecutor &
+    ElementSimilarityBlueprint::createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const {
+        std::vector<OutputSpec> output_specs;
+        for (const auto &output: _outputs) {
+            output_specs.emplace_back(output->compile_token->get().get_function<5>(),
+                                      output->aggregator_factory->create());
+        }
+        return stash.create<ElementSimilarityExecutor>(VectorizedQueryTerms(env, _field_id), std::move(output_specs));
     }
-    return stash.create<ElementSimilarityExecutor>(VectorizedQueryTerms(env, _field_id), std::move(output_specs));
-}
 
 //-----------------------------------------------------------------------------
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/element_similarity_feature.h b/searchlib/src/vespa/searchlib/features/element_similarity_feature.h
index 658cb872750..1c07a28b5d9 100644
--- a/searchlib/src/vespa/searchlib/features/element_similarity_feature.h
+++ b/searchlib/src/vespa/searchlib/features/element_similarity_feature.h
@@ -2,11 +2,10 @@
 
 #pragma once
 
-#include <vespa/searchlib/fef/fef.h>
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/vespalib/util/priority_queue.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
@@ -34,8 +33,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-//-----------------------------------------------------------------------------
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/euclidean_distance_feature.h b/searchlib/src/vespa/searchlib/features/euclidean_distance_feature.h
index ba3f0b6da34..7825b286649 100644
--- a/searchlib/src/vespa/searchlib/features/euclidean_distance_feature.h
+++ b/searchlib/src/vespa/searchlib/features/euclidean_distance_feature.h
@@ -3,13 +3,9 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchcommon/attribute/attributecontent.h>
 
-
-namespace search {
-namespace features {
-
+namespace search::features {
 
 /**
  * Implements the executor for the eucledian distance feature.
@@ -31,7 +27,7 @@ private:
 public:
 
     EuclideanDistanceExecutor(const search::attribute::IAttributeVector &attribute, QueryVectorType vector);
-    virtual void execute(uint32_t docId) override;
+    void execute(uint32_t docId) override;
 };
 
 
@@ -57,7 +53,4 @@ public:
 
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/fieldinfofeature.h b/searchlib/src/vespa/searchlib/features/fieldinfofeature.h
index 7ced5d5cb9f..f8d45d83af6 100644
--- a/searchlib/src/vespa/searchlib/features/fieldinfofeature.h
+++ b/searchlib/src/vespa/searchlib/features/fieldinfofeature.h
@@ -3,11 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class IndexFieldInfoExecutor : public fef::FeatureExecutor
 {
@@ -67,6 +64,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &queryEnv, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/fieldlengthfeature.h b/searchlib/src/vespa/searchlib/features/fieldlengthfeature.h
index 4988bb97546..31b02b7d8fc 100644
--- a/searchlib/src/vespa/searchlib/features/fieldlengthfeature.h
+++ b/searchlib/src/vespa/searchlib/features/fieldlengthfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for field length.
@@ -15,7 +13,7 @@ private:
     std::vector<fef::TermFieldHandle> _fieldHandles;
     const fef::MatchData             *_md;
 
-    virtual void handle_bind_match_data(const fef::MatchData &md) override;
+    void handle_bind_match_data(const fef::MatchData &md) override;
 
 public:
     /**
@@ -48,5 +46,4 @@ public:
     bool setup(const fef::IIndexEnvironment & env, const fef::ParameterList & params) override;
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/fieldmatchfeature.h b/searchlib/src/vespa/searchlib/features/fieldmatchfeature.h
index 71ac1023df6..1f21364b294 100644
--- a/searchlib/src/vespa/searchlib/features/fieldmatchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/fieldmatchfeature.h
@@ -2,12 +2,11 @@
 
 #pragma once
 
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/searchlib/features/fieldmatch/computer.h>
 #include <vespa/searchlib/features/fieldmatch/params.h>
-#include <vespa/searchlib/fef/blueprint.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for THE field match feature.
@@ -52,6 +51,5 @@ public:
     bool setup(const fef::IIndexEnvironment & env, const fef::ParameterList & params) override;
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
-    
-} // namespace features
-} // namespace search
+
+}
diff --git a/searchlib/src/vespa/searchlib/features/fieldtermmatchfeature.h b/searchlib/src/vespa/searchlib/features/fieldtermmatchfeature.h
index 0f89f7eeb75..c69014bb184 100644
--- a/searchlib/src/vespa/searchlib/features/fieldtermmatchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/fieldtermmatchfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for term feature.
@@ -49,5 +47,4 @@ private:
     uint32_t _termId;
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/firstphasefeature.h b/searchlib/src/vespa/searchlib/features/firstphasefeature.h
index baf640d1492..5edd7a7ce0a 100644
--- a/searchlib/src/vespa/searchlib/features/firstphasefeature.h
+++ b/searchlib/src/vespa/searchlib/features/firstphasefeature.h
@@ -4,8 +4,7 @@
 
 #include <vespa/searchlib/fef/blueprint.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor outputting the first phase ranking.
@@ -33,6 +32,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/flow_completeness_feature.cpp b/searchlib/src/vespa/searchlib/features/flow_completeness_feature.cpp
index c46d602983d..871c53221c8 100644
--- a/searchlib/src/vespa/searchlib/features/flow_completeness_feature.cpp
+++ b/searchlib/src/vespa/searchlib/features/flow_completeness_feature.cpp
@@ -1,17 +1,20 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "flow_completeness_feature.h"
+#include <vespa/searchlib/fef/itermdata.h>
+#include <vespa/searchlib/fef/featurenamebuilder.h>
+#include <vespa/searchlib/fef/properties.h>
+#include <vespa/searchlib/fef/indexproperties.h>
 #include <vespa/vespalib/stllike/hash_map.h>
 #include <vespa/vespalib/locale/c.h>
 #include <vespa/log/log.h>
 LOG_SETUP(".features.flowcompleteness");
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
-FlowCompletenessExecutor::FlowCompletenessExecutor(const search::fef::IQueryEnvironment &env,
+FlowCompletenessExecutor::FlowCompletenessExecutor(const fef::IQueryEnvironment &env,
                                                    const FlowCompletenessParams &params)
     : _params(params),
       _terms(),
@@ -20,13 +23,13 @@ FlowCompletenessExecutor::FlowCompletenessExecutor(const search::fef::IQueryEnvi
 {
     for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
         LOG(spam, "consider term %u", i);
-        const search::fef::ITermData *termData = env.getTerm(i);
+        const fef::ITermData *termData = env.getTerm(i);
         LOG(spam, "term %u weight %u", i, termData->getWeight().percent());
         if (termData->getWeight().percent() != 0) { // only consider query terms with contribution
-            typedef search::fef::ITermFieldRangeAdapter FRA;
+            typedef fef::ITermFieldRangeAdapter FRA;
             uint32_t j = 0;
             for (FRA iter(*termData); iter.valid(); iter.next()) {
-                const search::fef::ITermFieldData &tfd = iter.get();
+                const fef::ITermFieldData &tfd = iter.get();
                 LOG(spam, "term %u field data %u for field id %u (my field id %u)",
                     i, j++, tfd.getFieldId(), _params.fieldId);
                 if (tfd.getFieldId() == _params.fieldId) {
@@ -184,7 +187,7 @@ FlowCompletenessExecutor::execute(uint32_t)
 {
     assert(_queue.empty());
     for (size_t i = 0; i < _terms.size(); ++i) {
-        const search::fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms[i].termHandle);
+        const fef::TermFieldMatchData *tfmd = _md->resolveTermField(_terms[i].termHandle);
         Item item(i, tfmd->begin(), tfmd->end());
         LOG(spam, "found tfmd item with %zu positions", (item.end - item.pos));
         if (item.pos != item.end) {
@@ -255,15 +258,15 @@ FlowCompletenessBlueprint::FlowCompletenessBlueprint()
 }
 
 void
-FlowCompletenessBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironment &env,
-                                             search::fef::IDumpFeatureVisitor &visitor) const
+FlowCompletenessBlueprint::visitDumpFeatures(const fef::IIndexEnvironment &env,
+                                             fef::IDumpFeatureVisitor &visitor) const
 {
 #ifdef notyet
     for (uint32_t i = 0; i < env.getNumFields(); ++i) {
-        const search::fef::FieldInfo &field = *env.getField(i);
-        if (field.type() == search::fef::FieldType::INDEX) {
+        const fef::FieldInfo &field = *env.getField(i);
+        if (field.type() == fef::FieldType::INDEX) {
             if (!field.isFilter()) {
-                search::fef::FeatureNameBuilder fnb;
+                fef::FeatureNameBuilder fnb;
                 fnb.baseName(getBaseName()).parameter(field.name());
                 for (size_t out = 0; out < _output.size(); ++out) {
                     visitor.visitDumpFeature(fnb.output(_output[out]).buildName());
@@ -277,25 +280,25 @@ FlowCompletenessBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironmen
 #endif
 }
 
-search::fef::Blueprint::UP
+fef::Blueprint::UP
 FlowCompletenessBlueprint::createInstance() const
 {
     return Blueprint::UP(new FlowCompletenessBlueprint());
 }
 
 bool
-FlowCompletenessBlueprint::setup(const search::fef::IIndexEnvironment &env,
-                                 const search::fef::ParameterList &params)
+FlowCompletenessBlueprint::setup(const fef::IIndexEnvironment &env,
+                                 const fef::ParameterList &params)
 {
-    const search::fef::FieldInfo *field = params[0].asField();
+    const fef::FieldInfo *field = params[0].asField();
 
     _params.fieldId = field->id();
-    const search::fef::Properties &lst = env.getProperties();
-    search::fef::Property obj = lst.lookup(getName(), "fieldCompletenessImportance");
+    const fef::Properties &lst = env.getProperties();
+    fef::Property obj = lst.lookup(getName(), "fieldCompletenessImportance");
     if (obj.found()) {
         _params.fieldCompletenessImportance = vespalib::locale::c::atof(obj.get().c_str());
     }
-    _params.fieldWeight = search::fef::indexproperties::FieldWeight::lookup(lst, field->name());
+    _params.fieldWeight = fef::indexproperties::FieldWeight::lookup(lst, field->name());
 
     describeOutput(_output[0], "combined completeness for best scored element");
     describeOutput(_output[1], "best scored element completeness");
@@ -307,13 +310,12 @@ FlowCompletenessBlueprint::setup(const search::fef::IIndexEnvironment &env,
     return true;
 }
 
-search::fef::FeatureExecutor &
-FlowCompletenessBlueprint::createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const
+fef::FeatureExecutor &
+FlowCompletenessBlueprint::createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const
 {
     return stash.create<FlowCompletenessExecutor>(env, _params);
 }
 
 //-----------------------------------------------------------------------------
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/flow_completeness_feature.h b/searchlib/src/vespa/searchlib/features/flow_completeness_feature.h
index db5c53beac8..cb3a71950ae 100644
--- a/searchlib/src/vespa/searchlib/features/flow_completeness_feature.h
+++ b/searchlib/src/vespa/searchlib/features/flow_completeness_feature.h
@@ -2,7 +2,7 @@
 
 #pragma once
 
-#include <vespa/searchlib/fef/fef.h>
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/vespalib/util/priority_queue.h>
 
 namespace search::features {
diff --git a/searchlib/src/vespa/searchlib/features/foreachfeature.h b/searchlib/src/vespa/searchlib/features/foreachfeature.h
index 955724fb9c2..0eba4e36528 100644
--- a/searchlib/src/vespa/searchlib/features/foreachfeature.h
+++ b/searchlib/src/vespa/searchlib/features/foreachfeature.h
@@ -3,11 +3,9 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <limits>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the foreach feature.
@@ -163,7 +161,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/freshnessfeature.h b/searchlib/src/vespa/searchlib/features/freshnessfeature.h
index e156cad53ed..1512a3255ad 100644
--- a/searchlib/src/vespa/searchlib/features/freshnessfeature.h
+++ b/searchlib/src/vespa/searchlib/features/freshnessfeature.h
@@ -4,10 +4,8 @@
 
 #include "logarithmcalculator.h"
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the freshness feature.
@@ -42,7 +40,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/item_raw_score_feature.h b/searchlib/src/vespa/searchlib/features/item_raw_score_feature.h
index d6a55f29632..5bc7602e259 100644
--- a/searchlib/src/vespa/searchlib/features/item_raw_score_feature.h
+++ b/searchlib/src/vespa/searchlib/features/item_raw_score_feature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class ItemRawScoreExecutor : public fef::FeatureExecutor
 {
@@ -61,6 +59,4 @@ public:
     static HandleVector resolve(const fef::IQueryEnvironment &env, const vespalib::string &label);
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/jarowinklerdistancefeature.h b/searchlib/src/vespa/searchlib/features/jarowinklerdistancefeature.h
index a8d6eacf0eb..3c3f00eda8e 100644
--- a/searchlib/src/vespa/searchlib/features/jarowinklerdistancefeature.h
+++ b/searchlib/src/vespa/searchlib/features/jarowinklerdistancefeature.h
@@ -2,11 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the necessary config to pass from the jaro winkler distance blueprint to the executor.
@@ -68,5 +65,4 @@ private:
     JaroWinklerDistanceConfig _config; // The config for this blueprint.
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/logarithmcalculator.h b/searchlib/src/vespa/searchlib/features/logarithmcalculator.h
index d09f3a8e6ac..b223a6f2207 100644
--- a/searchlib/src/vespa/searchlib/features/logarithmcalculator.h
+++ b/searchlib/src/vespa/searchlib/features/logarithmcalculator.h
@@ -5,8 +5,7 @@
 #include <vespa/searchlib/common/feature.h>
 #include <cmath>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This class is used to calculate a logarithmic-shaped function that goes from 1 to 0.
@@ -57,6 +56,4 @@ public:
     }
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/matchcountfeature.h b/searchlib/src/vespa/searchlib/features/matchcountfeature.h
index eadb5064c57..a81f4f084b8 100644
--- a/searchlib/src/vespa/searchlib/features/matchcountfeature.h
+++ b/searchlib/src/vespa/searchlib/features/matchcountfeature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the matchCount feature for index and
@@ -18,7 +16,7 @@ private:
     std::vector<fef::TermFieldHandle> _handles;
     const fef::MatchData             *_md;
 
-    virtual void handle_bind_match_data(const fef::MatchData &md) override;
+    void handle_bind_match_data(const fef::MatchData &md) override;
 
 public:
     MatchCountExecutor(uint32_t fieldId, const fef::IQueryEnvironment &env);
@@ -54,6 +52,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/matchesfeature.h b/searchlib/src/vespa/searchlib/features/matchesfeature.h
index c6366349dd9..53c6151a713 100644
--- a/searchlib/src/vespa/searchlib/features/matchesfeature.h
+++ b/searchlib/src/vespa/searchlib/features/matchesfeature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the matches feature for index and
@@ -52,6 +50,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/matchfeature.h b/searchlib/src/vespa/searchlib/features/matchfeature.h
index 64d931a08d8..de3205aa7a1 100644
--- a/searchlib/src/vespa/searchlib/features/matchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/matchfeature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 struct MatchParams {
     MatchParams() : weights() {}
@@ -45,7 +43,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/native_dot_product_feature.h b/searchlib/src/vespa/searchlib/features/native_dot_product_feature.h
index 33c5c89c88b..0d7c75c7cf7 100644
--- a/searchlib/src/vespa/searchlib/features/native_dot_product_feature.h
+++ b/searchlib/src/vespa/searchlib/features/native_dot_product_feature.h
@@ -3,12 +3,10 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/query/weight.h>
 #include <algorithm>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class NativeDotProductExecutor : public fef::FeatureExecutor
 {
@@ -44,6 +42,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/nativeattributematchfeature.h b/searchlib/src/vespa/searchlib/features/nativeattributematchfeature.h
index e2c9dc7aef1..0f897c76fc4 100644
--- a/searchlib/src/vespa/searchlib/features/nativeattributematchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/nativeattributematchfeature.h
@@ -7,8 +7,7 @@
 #include <vespa/searchlib/fef/itermfielddata.h>
 #include <vespa/searchlib/fef/symmetrictable.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This struct contains parameters used by the executor.
@@ -101,6 +100,4 @@ public:
     const NativeAttributeMatchParams & getParams() const { return _params; }
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/nativefieldmatchfeature.h b/searchlib/src/vespa/searchlib/features/nativefieldmatchfeature.h
index cb676e5b775..539b64ced16 100644
--- a/searchlib/src/vespa/searchlib/features/nativefieldmatchfeature.h
+++ b/searchlib/src/vespa/searchlib/features/nativefieldmatchfeature.h
@@ -6,8 +6,7 @@
 #include "queryterm.h"
 #include <vespa/fastos/dynamiclibrary.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This struct contains parameters used by the executor.
@@ -114,7 +113,4 @@ public:
     const NativeFieldMatchParams & getParams() const { return _params; }
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/nativeproximityfeature.h b/searchlib/src/vespa/searchlib/features/nativeproximityfeature.h
index f98fe2bfd22..13f2ea2dbcd 100644
--- a/searchlib/src/vespa/searchlib/features/nativeproximityfeature.h
+++ b/searchlib/src/vespa/searchlib/features/nativeproximityfeature.h
@@ -6,8 +6,7 @@
 #include "queryterm.h"
 #include "termdistancecalculator.h"
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This struct contains parameters used by the executor.
@@ -98,7 +97,4 @@ public:
     const NativeProximityParams & getParams() const { return _params; }
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/nativerankfeature.h b/searchlib/src/vespa/searchlib/features/nativerankfeature.h
index db43b7cf4f5..3b8ddccaa1d 100644
--- a/searchlib/src/vespa/searchlib/features/nativerankfeature.h
+++ b/searchlib/src/vespa/searchlib/features/nativerankfeature.h
@@ -3,12 +3,10 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/fef/fieldtype.h>
 #include <vespa/searchlib/fef/table.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This struct contains parameters used by the nativeRank executor.
@@ -116,6 +114,4 @@ public:
     static bool useTableNormalization(const fef::IIndexEnvironment & env);
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/nowfeature.h b/searchlib/src/vespa/searchlib/features/nowfeature.h
index 867a8c15855..e9191689fb2 100644
--- a/searchlib/src/vespa/searchlib/features/nowfeature.h
+++ b/searchlib/src/vespa/searchlib/features/nowfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for the 'now' feature. This executor returns the current
@@ -43,5 +41,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/proximityfeature.h b/searchlib/src/vespa/searchlib/features/proximityfeature.h
index 14a80628004..5cb8adaa287 100644
--- a/searchlib/src/vespa/searchlib/features/proximityfeature.h
+++ b/searchlib/src/vespa/searchlib/features/proximityfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the necessary config for proximity.
@@ -62,4 +60,4 @@ private:
     ProximityConfig _config;
 };
 
-}}
+}
diff --git a/searchlib/src/vespa/searchlib/features/querycompletenessfeature.h b/searchlib/src/vespa/searchlib/features/querycompletenessfeature.h
index a5e6bbdc2bb..3c0efdecf58 100644
--- a/searchlib/src/vespa/searchlib/features/querycompletenessfeature.h
+++ b/searchlib/src/vespa/searchlib/features/querycompletenessfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the necessary config for query completeness.
@@ -63,5 +61,4 @@ private:
     QueryCompletenessConfig _config;
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/queryfeature.h b/searchlib/src/vespa/searchlib/features/queryfeature.h
index 779153437d4..0d4424db792 100644
--- a/searchlib/src/vespa/searchlib/features/queryfeature.h
+++ b/searchlib/src/vespa/searchlib/features/queryfeature.h
@@ -5,8 +5,7 @@
 #include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/eval/eval/value_type.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the blueprint for the query feature.
@@ -34,6 +33,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/queryterm.cpp b/searchlib/src/vespa/searchlib/features/queryterm.cpp
index 8b43df28178..84423493eb5 100644
--- a/searchlib/src/vespa/searchlib/features/queryterm.cpp
+++ b/searchlib/src/vespa/searchlib/features/queryterm.cpp
@@ -6,8 +6,7 @@
 using namespace search::fef;
 using search::feature_t;
 
-namespace search {
-namespace features {
+namespace search::features {
 
 QueryTerm::QueryTerm() :
     _termData(NULL),
@@ -45,5 +44,4 @@ QueryTermFactory::create(const IQueryEnvironment & env,
 }
 
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/querytermcountfeature.h b/searchlib/src/vespa/searchlib/features/querytermcountfeature.h
index 39b85756c07..f31fb1daf18 100644
--- a/searchlib/src/vespa/searchlib/features/querytermcountfeature.h
+++ b/searchlib/src/vespa/searchlib/features/querytermcountfeature.h
@@ -3,11 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the blueprint for the query term count feature.
@@ -26,7 +23,4 @@ public:
     search::fef::FeatureExecutor &createExecutor(const search::fef::IQueryEnvironment & env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/random_normal_feature.h b/searchlib/src/vespa/searchlib/features/random_normal_feature.h
index adf3d3be63f..bf0aa66ea36 100644
--- a/searchlib/src/vespa/searchlib/features/random_normal_feature.h
+++ b/searchlib/src/vespa/searchlib/features/random_normal_feature.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/util/random_normal.h>
 
 namespace search::features {
diff --git a/searchlib/src/vespa/searchlib/features/random_normal_stable_feature.h b/searchlib/src/vespa/searchlib/features/random_normal_stable_feature.h
index ab9a53a2df3..6211999a4f6 100644
--- a/searchlib/src/vespa/searchlib/features/random_normal_stable_feature.h
+++ b/searchlib/src/vespa/searchlib/features/random_normal_stable_feature.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/util/random_normal.h>
 
 namespace search::features {
diff --git a/searchlib/src/vespa/searchlib/features/randomfeature.h b/searchlib/src/vespa/searchlib/features/randomfeature.h
index 8ed0e403836..8c94b71071f 100644
--- a/searchlib/src/vespa/searchlib/features/randomfeature.h
+++ b/searchlib/src/vespa/searchlib/features/randomfeature.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/util/rand48.h>
 
 namespace search::features {
diff --git a/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.h b/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.h
index 85514a4def7..8d5144206ea 100644
--- a/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.h
+++ b/searchlib/src/vespa/searchlib/features/rankingexpressionfeature.h
@@ -2,7 +2,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/eval/eval/interpreted_function.h>
 #include <vespa/eval/eval/llvm/compile_cache.h>
 #include <vespa/searchlib/features/rankingexpression/expression_replacer.h>
diff --git a/searchlib/src/vespa/searchlib/features/raw_score_feature.h b/searchlib/src/vespa/searchlib/features/raw_score_feature.h
index db237f036c4..2a4eb946a68 100644
--- a/searchlib/src/vespa/searchlib/features/raw_score_feature.h
+++ b/searchlib/src/vespa/searchlib/features/raw_score_feature.h
@@ -3,7 +3,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
 namespace search::features {
 
diff --git a/searchlib/src/vespa/searchlib/features/reverseproximityfeature.h b/searchlib/src/vespa/searchlib/features/reverseproximityfeature.h
index 776dde39f77..d06b6c57fe7 100644
--- a/searchlib/src/vespa/searchlib/features/reverseproximityfeature.h
+++ b/searchlib/src/vespa/searchlib/features/reverseproximityfeature.h
@@ -2,10 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the necessary config for reverse proximity.
@@ -59,5 +57,4 @@ private:
     ReverseProximityConfig _config;
 };
 
-}}
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/setup.cpp b/searchlib/src/vespa/searchlib/features/setup.cpp
index 1d3c59f5b3d..a4a9689b971 100644
--- a/searchlib/src/vespa/searchlib/features/setup.cpp
+++ b/searchlib/src/vespa/searchlib/features/setup.cpp
@@ -54,15 +54,14 @@
 #include "valuefeature.h"
 #include "constant_feature.h"
 
-#include <vespa/searchlib/features/max_reduce_prod_join_replacer.h>
+#include "max_reduce_prod_join_replacer.h"
 #include <vespa/searchlib/features/rankingexpression/expression_replacer.h>
 
 using search::fef::Blueprint;
 using search::features::rankingexpression::ListExpressionReplacer;
 using search::features::MaxReduceProdJoinReplacer;
 
-namespace search {
-namespace features {
+namespace search::features {
 
 void setup_search_features(fef::IBlueprintRegistry & registry)
 {
@@ -127,5 +126,4 @@ void setup_search_features(fef::IBlueprintRegistry & registry)
     registry.addPrototype(std::make_shared<RankingExpressionBlueprint>(std::move(replacers)));
 }
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/setup.h b/searchlib/src/vespa/searchlib/features/setup.h
index 3c3057250bf..3904882c3a8 100644
--- a/searchlib/src/vespa/searchlib/features/setup.h
+++ b/searchlib/src/vespa/searchlib/features/setup.h
@@ -4,8 +4,7 @@
 #include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/searchlib/fef/iblueprintregistry.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Adds prototypes for all features in this library to the given registry.
@@ -14,6 +13,4 @@ namespace features {
  **/
 void setup_search_features(fef::IBlueprintRegistry & registry);
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/subqueries_feature.h b/searchlib/src/vespa/searchlib/features/subqueries_feature.h
index 136d8d90f94..3a6be567548 100644
--- a/searchlib/src/vespa/searchlib/features/subqueries_feature.h
+++ b/searchlib/src/vespa/searchlib/features/subqueries_feature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class SubqueriesExecutor : public fef::FeatureExecutor {
     std::vector<fef::TermFieldHandle> _handles;
@@ -37,6 +35,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/tensor_attribute_executor.h b/searchlib/src/vespa/searchlib/features/tensor_attribute_executor.h
index 3f981e06482..2b2e1e6e4f1 100644
--- a/searchlib/src/vespa/searchlib/features/tensor_attribute_executor.h
+++ b/searchlib/src/vespa/searchlib/features/tensor_attribute_executor.h
@@ -8,9 +8,8 @@
 #include <vespa/vespalib/stllike/string.h>
 #include <vespa/eval/tensor/default_tensor.h>
 
-namespace search {
-namespace tensor { class ITensorAttribute; }
-namespace features {
+namespace search::tensor { class ITensorAttribute; }
+namespace search::features {
 
 class TensorAttributeExecutor : public fef::FeatureExecutor
 {
@@ -24,5 +23,4 @@ public:
     void execute(uint32_t docId) override;
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/tensor_factory_blueprint.h b/searchlib/src/vespa/searchlib/features/tensor_factory_blueprint.h
index eb75b851bb9..c2b6534ae74 100644
--- a/searchlib/src/vespa/searchlib/features/tensor_factory_blueprint.h
+++ b/searchlib/src/vespa/searchlib/features/tensor_factory_blueprint.h
@@ -5,13 +5,12 @@
 #include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/vespalib/stllike/string.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Factory class for tensor rank features.
  */
-class TensorFactoryBlueprint : public search::fef::Blueprint
+class TensorFactoryBlueprint : public fef::Blueprint
 {
 protected:
     static vespalib::string ATTRIBUTE_SOURCE;
@@ -26,9 +25,8 @@ protected:
     ~TensorFactoryBlueprint();
 
 public:
-    void visitDumpFeatures(const search::fef::IIndexEnvironment &,
-                           search::fef::IDumpFeatureVisitor &) const override {}
+    void visitDumpFeatures(const fef::IIndexEnvironment &,
+                           fef::IDumpFeatureVisitor &) const override {}
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/tensor_from_attribute_executor.h b/searchlib/src/vespa/searchlib/features/tensor_from_attribute_executor.h
index f102749f1b6..4c5f64611c1 100644
--- a/searchlib/src/vespa/searchlib/features/tensor_from_attribute_executor.h
+++ b/searchlib/src/vespa/searchlib/features/tensor_from_attribute_executor.h
@@ -3,13 +3,11 @@
 #pragma once
 
 #include <vespa/searchcommon/attribute/iattributevector.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/eval/eval/value.h>
 #include <vespa/vespalib/stllike/string.h>
 #include <vespa/eval/tensor/default_tensor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Feature executor that extracts the content from an attribute vector
@@ -52,5 +50,4 @@ TensorFromAttributeExecutor<WeightedBufferType>::execute(uint32_t docId)
     outputs().set_object(0, *_tensor);
 }
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/tensor_from_labels_feature.h b/searchlib/src/vespa/searchlib/features/tensor_from_labels_feature.h
index 4d06088bcff..e014b040eb1 100644
--- a/searchlib/src/vespa/searchlib/features/tensor_from_labels_feature.h
+++ b/searchlib/src/vespa/searchlib/features/tensor_from_labels_feature.h
@@ -4,8 +4,7 @@
 
 #include "tensor_factory_blueprint.h"
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Blueprint for a rank feature that creates a tensor from an array
@@ -18,18 +17,16 @@ class TensorFromLabelsBlueprint : public TensorFactoryBlueprint
 {
 public:
     TensorFromLabelsBlueprint();
-    virtual search::fef::Blueprint::UP createInstance() const override {
+    fef::Blueprint::UP createInstance() const override {
         return Blueprint::UP(new TensorFromLabelsBlueprint());
     }
-    virtual search::fef::ParameterDescriptions getDescriptions() const override {
-        return search::fef::ParameterDescriptions().
+    fef::ParameterDescriptions getDescriptions() const override {
+        return fef::ParameterDescriptions().
             desc().string().
             desc().string().string();
     }
-    virtual bool setup(const search::fef::IIndexEnvironment &env,
-                       const search::fef::ParameterList &params) override;
-    virtual search::fef::FeatureExecutor &createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
+    bool setup(const fef::IIndexEnvironment &env, const fef::ParameterList &params) override;
+    fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/tensor_from_weighted_set_feature.h b/searchlib/src/vespa/searchlib/features/tensor_from_weighted_set_feature.h
index 5cae7f25476..367eab08076 100644
--- a/searchlib/src/vespa/searchlib/features/tensor_from_weighted_set_feature.h
+++ b/searchlib/src/vespa/searchlib/features/tensor_from_weighted_set_feature.h
@@ -4,8 +4,7 @@
 
 #include "tensor_factory_blueprint.h"
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Feature blueprint for a rank feature that creates a tensor from a weighted set.
@@ -15,18 +14,16 @@ class TensorFromWeightedSetBlueprint : public TensorFactoryBlueprint
 {
 public:
     TensorFromWeightedSetBlueprint();
-    virtual search::fef::Blueprint::UP createInstance() const override {
+    fef::Blueprint::UP createInstance() const override {
         return Blueprint::UP(new TensorFromWeightedSetBlueprint());
     }
-    virtual search::fef::ParameterDescriptions getDescriptions() const override {
-        return search::fef::ParameterDescriptions().
+    fef::ParameterDescriptions getDescriptions() const override {
+        return fef::ParameterDescriptions().
             desc().string().
             desc().string().string();
     }
-    virtual bool setup(const search::fef::IIndexEnvironment &env,
-                       const search::fef::ParameterList &params) override;
-    virtual search::fef::FeatureExecutor &createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
+    bool setup(const fef::IIndexEnvironment &env, const fef::ParameterList &params) override;
+    fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/term_field_md_feature.h b/searchlib/src/vespa/searchlib/features/term_field_md_feature.h
index df9ab982dcb..fca101f85d4 100644
--- a/searchlib/src/vespa/searchlib/features/term_field_md_feature.h
+++ b/searchlib/src/vespa/searchlib/features/term_field_md_feature.h
@@ -3,13 +3,11 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/fef/table.h>
 #include <vespa/searchlib/fef/itermdata.h>
 #include <vespa/searchlib/fef/itermfielddata.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for looking at term field match data
@@ -43,6 +41,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment & env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/termdistancecalculator.h b/searchlib/src/vespa/searchlib/features/termdistancecalculator.h
index ebda2b8daa1..e606e8666e3 100644
--- a/searchlib/src/vespa/searchlib/features/termdistancecalculator.h
+++ b/searchlib/src/vespa/searchlib/features/termdistancecalculator.h
@@ -4,14 +4,12 @@
 
 #include "queryterm.h"
 
-namespace search {
-
-namespace fef {
+namespace search::fef {
     class TermFieldMatchData;
     class MatchData;
 }
 
-namespace features {
+namespace search::features {
 
 /**
  * This class is used to calculate the minimal forward and reverse term distance
@@ -82,5 +80,4 @@ public:
                     const fef::MatchData & match, uint32_t docId, Result & r);
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/termdistancefeature.h b/searchlib/src/vespa/searchlib/features/termdistancefeature.h
index 8e153072bc2..276476de21b 100644
--- a/searchlib/src/vespa/searchlib/features/termdistancefeature.h
+++ b/searchlib/src/vespa/searchlib/features/termdistancefeature.h
@@ -3,12 +3,10 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 #include <vespa/searchlib/fef/table.h>
 #include "termdistancecalculator.h"
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * This struct contains parameters used by the executor.
@@ -59,6 +57,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/termeditdistancefeature.h b/searchlib/src/vespa/searchlib/features/termeditdistancefeature.h
index ea5974495ea..6d5739c690f 100644
--- a/searchlib/src/vespa/searchlib/features/termeditdistancefeature.h
+++ b/searchlib/src/vespa/searchlib/features/termeditdistancefeature.h
@@ -2,8 +2,6 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 
 namespace search::features {
 
diff --git a/searchlib/src/vespa/searchlib/features/termfeature.h b/searchlib/src/vespa/searchlib/features/termfeature.h
index 9821bb4eb69..cb1a8621795 100644
--- a/searchlib/src/vespa/searchlib/features/termfeature.h
+++ b/searchlib/src/vespa/searchlib/features/termfeature.h
@@ -2,11 +2,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Implements the executor for term feature.
@@ -47,4 +44,4 @@ private:
     uint32_t _termId;
 };
 
-}}
+}
diff --git a/searchlib/src/vespa/searchlib/features/terminfofeature.h b/searchlib/src/vespa/searchlib/features/terminfofeature.h
index b05762972bf..0197e339e38 100644
--- a/searchlib/src/vespa/searchlib/features/terminfofeature.h
+++ b/searchlib/src/vespa/searchlib/features/terminfofeature.h
@@ -3,10 +3,8 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class TermInfoBlueprint : public fef::Blueprint
 {
@@ -24,6 +22,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &queryEnv, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/text_similarity_feature.cpp b/searchlib/src/vespa/searchlib/features/text_similarity_feature.cpp
index a50f042b552..c445241fe59 100644
--- a/searchlib/src/vespa/searchlib/features/text_similarity_feature.cpp
+++ b/searchlib/src/vespa/searchlib/features/text_similarity_feature.cpp
@@ -1,20 +1,20 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "text_similarity_feature.h"
+#include <vespa/searchlib/fef/itermdata.h>
+#include <vespa/searchlib/fef/featurenamebuilder.h>
 
-namespace search {
+namespace search::features {
 
 using CollectionType = fef::FieldInfo::CollectionType;
 
-namespace features {
-
 namespace {
 
 struct Term {
-    search::fef::TermFieldHandle handle;
+    fef::TermFieldHandle handle;
     int                          weight;
     int                          index;
-    Term(search::fef::TermFieldHandle handle_in, int weight_in, int index_in)
+    Term(fef::TermFieldHandle handle_in, int weight_in, int index_in)
         : handle(handle_in), weight(weight_in), index(index_in) {}
 };
 
@@ -74,7 +74,7 @@ struct State {
 
 //-----------------------------------------------------------------------------
 
-TextSimilarityExecutor::TextSimilarityExecutor(const search::fef::IQueryEnvironment &env,
+TextSimilarityExecutor::TextSimilarityExecutor(const fef::IQueryEnvironment &env,
                                                uint32_t field_id)
     : _handles(),
       _weights(),
@@ -84,11 +84,11 @@ TextSimilarityExecutor::TextSimilarityExecutor(const search::fef::IQueryEnvironm
 {
     std::vector<Term> terms;
     for (uint32_t i = 0; i < env.getNumTerms(); ++i) {
-        const search::fef::ITermData *termData = env.getTerm(i);
+        const fef::ITermData *termData = env.getTerm(i);
         if (termData->getWeight().percent() != 0) { // only consider query terms with contribution
-            typedef search::fef::ITermFieldRangeAdapter FRA;
+            typedef fef::ITermFieldRangeAdapter FRA;
             for (FRA iter(*termData); iter.valid(); iter.next()) {
-                const search::fef::ITermFieldData &tfd = iter.get();
+                const fef::ITermFieldData &tfd = iter.get();
                 if (tfd.getFieldId() == field_id) {
                     int term_weight = termData->getWeight().percent();
                     _total_term_weight += term_weight;
@@ -175,14 +175,14 @@ TextSimilarityBlueprint::TextSimilarityBlueprint()
     : Blueprint("textSimilarity"), _field_id(fef::IllegalHandle) {}
 
 void
-TextSimilarityBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironment &env,
-                                           search::fef::IDumpFeatureVisitor &visitor) const
+TextSimilarityBlueprint::visitDumpFeatures(const fef::IIndexEnvironment &env,
+                                           fef::IDumpFeatureVisitor &visitor) const
 {
     for (uint32_t i = 0; i < env.getNumFields(); ++i) {
-        const search::fef::FieldInfo &field = *env.getField(i);
-        if (field.type() == search::fef::FieldType::INDEX) {
+        const fef::FieldInfo &field = *env.getField(i);
+        if (field.type() == fef::FieldType::INDEX) {
             if (!field.isFilter() && field.collection() == CollectionType::SINGLE) {
-                search::fef::FeatureNameBuilder fnb;
+                fef::FeatureNameBuilder fnb;
                 fnb.baseName(getBaseName()).parameter(field.name());
                 visitor.visitDumpFeature(fnb.output(score_output).buildName());
                 visitor.visitDumpFeature(fnb.output(proximity_output).buildName());
@@ -194,17 +194,17 @@ TextSimilarityBlueprint::visitDumpFeatures(const search::fef::IIndexEnvironment
     }
 }
 
-search::fef::Blueprint::UP
+fef::Blueprint::UP
 TextSimilarityBlueprint::createInstance() const
 {
     return Blueprint::UP(new TextSimilarityBlueprint());
 }
 
 bool
-TextSimilarityBlueprint::setup(const search::fef::IIndexEnvironment &env,
-                               const search::fef::ParameterList &params)
+TextSimilarityBlueprint::setup(const fef::IIndexEnvironment &env,
+                               const fef::ParameterList &params)
 {
-    const search::fef::FieldInfo *field = params[0].asField();
+    const fef::FieldInfo *field = params[0].asField();
     _field_id = field->id();
     describeOutput(score_output, "default normalized combination of other outputs");
     describeOutput(proximity_output, "normalized match proximity score");
@@ -215,13 +215,12 @@ TextSimilarityBlueprint::setup(const search::fef::IIndexEnvironment &env,
     return true;
 }
 
-search::fef::FeatureExecutor &
-TextSimilarityBlueprint::createExecutor(const search::fef::IQueryEnvironment &env, vespalib::Stash &stash) const
+fef::FeatureExecutor &
+TextSimilarityBlueprint::createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const
 {
     return stash.create<TextSimilarityExecutor>(env, _field_id);
 }
 
 //-----------------------------------------------------------------------------
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/text_similarity_feature.h b/searchlib/src/vespa/searchlib/features/text_similarity_feature.h
index a660f3e3e30..00406dc4993 100644
--- a/searchlib/src/vespa/searchlib/features/text_similarity_feature.h
+++ b/searchlib/src/vespa/searchlib/features/text_similarity_feature.h
@@ -2,11 +2,10 @@
 
 #pragma once
 
-#include <vespa/searchlib/fef/fef.h>
+#include <vespa/searchlib/fef/blueprint.h>
 #include <vespa/vespalib/util/priority_queue.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 //-----------------------------------------------------------------------------
 
@@ -67,8 +66,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &env, vespalib::Stash &stash) const override;
 };
 
-//-----------------------------------------------------------------------------
-
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/utils.cpp b/searchlib/src/vespa/searchlib/features/utils.cpp
index e87d356a074..86558e89ec9 100644
--- a/searchlib/src/vespa/searchlib/features/utils.cpp
+++ b/searchlib/src/vespa/searchlib/features/utils.cpp
@@ -2,9 +2,7 @@
 
 #include "utils.hpp"
 
-namespace search {
-namespace features {
-namespace util {
+namespace search::features::util {
 
 template double strToNum<double>(vespalib::stringref str);
 template uint32_t strToNum<uint32_t>(vespalib::stringref str);
@@ -12,7 +10,4 @@ template uint64_t strToNum<uint64_t>(vespalib::stringref str);
 template int32_t strToNum<int32_t>(vespalib::stringref str);
 template int64_t strToNum<int64_t>(vespalib::stringref str);
 
-} // namespace util
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/utils.hpp b/searchlib/src/vespa/searchlib/features/utils.hpp
index 1620d71e31e..7e6987ca14e 100644
--- a/searchlib/src/vespa/searchlib/features/utils.hpp
+++ b/searchlib/src/vespa/searchlib/features/utils.hpp
@@ -6,9 +6,7 @@
 #include <vespa/vespalib/stllike/asciistream.h>
 #include <vespa/vespalib/util/exceptions.h>
 
-namespace search {
-namespace features {
-namespace util {
+namespace search::features::util {
 
 template <typename T>
 T strToNum(vespalib::stringref str)
@@ -22,7 +20,5 @@ T strToNum(vespalib::stringref str)
     return retval;
 }
 
-} // namespace util
-} // namespace features
-} // namespace search
+}
 
diff --git a/searchlib/src/vespa/searchlib/features/valuefeature.h b/searchlib/src/vespa/searchlib/features/valuefeature.h
index cb2d188d164..1cc6bd55bc1 100644
--- a/searchlib/src/vespa/searchlib/features/valuefeature.h
+++ b/searchlib/src/vespa/searchlib/features/valuefeature.h
@@ -3,12 +3,9 @@
 #pragma once
 
 #include <vespa/searchlib/fef/blueprint.h>
-#include <vespa/searchlib/fef/featureexecutor.h>
-#include <vespa/searchlib/common/feature.h>
 #include <vector>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 class ValueExecutor : public fef::FeatureExecutor
 {
@@ -51,6 +48,4 @@ public:
     fef::FeatureExecutor &createExecutor(const fef::IQueryEnvironment &queryEnv, vespalib::Stash &stash) const override;
 };
 
-} // namespace features
-} // namespace search
-
+}
diff --git a/searchlib/src/vespa/searchlib/features/weighted_set_parser.h b/searchlib/src/vespa/searchlib/features/weighted_set_parser.h
index 5a778ebf698..8eedd9d98b6 100644
--- a/searchlib/src/vespa/searchlib/features/weighted_set_parser.h
+++ b/searchlib/src/vespa/searchlib/features/weighted_set_parser.h
@@ -4,8 +4,7 @@
 
 #include <vespa/vespalib/stllike/string.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 /**
  * Utility for parsing a string representation of a weighted set
@@ -24,5 +23,4 @@ public:
     static void parse(const vespalib::string &input, OutputType &output);
 };
 
-} // namespace features
-} // namespace search
+}
diff --git a/searchlib/src/vespa/searchlib/features/weighted_set_parser.hpp b/searchlib/src/vespa/searchlib/features/weighted_set_parser.hpp
index d67b089f5fe..1b3679bbf19 100644
--- a/searchlib/src/vespa/searchlib/features/weighted_set_parser.hpp
+++ b/searchlib/src/vespa/searchlib/features/weighted_set_parser.hpp
@@ -5,8 +5,7 @@
 #include "weighted_set_parser.h"
 #include <vespa/vespalib/util/stringfmt.h>
 
-namespace search {
-namespace features {
+namespace search::features {
 
 template <typename OutputType>
 void
@@ -44,5 +43,4 @@ WeightedSetParser::parse(const vespalib::string &input, OutputType &output)
     }
 }
 
-} // namespace features
-} // namespace search
+}