Use std::unique_ptr<vsm::FieldSearcher> to store field searhers.

24 files changed, 91 insertions, 42 deletions

diff --git a/vsm/src/vespa/vsm/searcher/boolfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/boolfieldsearcher.cpp
index bf40a679bab..a9f765546a8 100644
--- a/vsm/src/vespa/vsm/searcher/boolfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/boolfieldsearcher.cpp
@@ -12,7 +12,11 @@ vespalib::stringref TRUE = "true";
 vespalib::stringref FALSE = "false";
 }
 
-IMPLEMENT_DUPLICATE(BoolFieldSearcher);
+std::unique_ptr<FieldSearcher>
+BoolFieldSearcher::duplicate() const
+{
+    return std::make_unique<BoolFieldSearcher>(*this);
+}
 
 BoolFieldSearcher::BoolFieldSearcher(FieldIdT fId) :
     FieldSearcher(fId),
diff --git a/vsm/src/vespa/vsm/searcher/boolfieldsearcher.h b/vsm/src/vespa/vsm/searcher/boolfieldsearcher.h
index 139645bf0ba..b7f9419465d 100644
--- a/vsm/src/vespa/vsm/searcher/boolfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/boolfieldsearcher.h
@@ -8,7 +8,7 @@ namespace vsm {
 class BoolFieldSearcher : public FieldSearcher
 {
 public:
-    DUPLICATE(BoolFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     BoolFieldSearcher(FieldIdT fId);
     ~BoolFieldSearcher();
     void prepare(search::QueryTermList & qtl, const SharedSearcherBuf & buf) override;
diff --git a/vsm/src/vespa/vsm/searcher/fieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/fieldsearcher.cpp
index 2ba5fea3153..4bb36d3f968 100644
--- a/vsm/src/vespa/vsm/searcher/fieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/fieldsearcher.cpp
@@ -69,7 +69,6 @@ void FieldSearcherBase::prepare(const QueryTermList & qtl)
 
 FieldSearcher::FieldSearcher(const FieldIdT & fId, bool defaultPrefix) :
     FieldSearcherBase(),
-    Object(),
     _field(fId),
     _matchType(defaultPrefix ? PREFIX : REGULAR),
     _maxFieldLength(0x100000),
diff --git a/vsm/src/vespa/vsm/searcher/fieldsearcher.h b/vsm/src/vespa/vsm/searcher/fieldsearcher.h
index 2bf976de017..8bfb5a3af31 100644
--- a/vsm/src/vespa/vsm/searcher/fieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/fieldsearcher.h
@@ -38,7 +38,7 @@ protected:
     search::v16qi  *_qtlFast;
 };
 
-class FieldSearcher : public FieldSearcherBase, public search::Object
+class FieldSearcher : public FieldSearcherBase
 {
 public:
     enum MatchType {
@@ -50,7 +50,8 @@ public:
     };
 
     FieldSearcher(const FieldIdT & fId, bool defaultPrefix=false);
-    ~FieldSearcher();
+    ~FieldSearcher() override;
+    virtual std::unique_ptr<FieldSearcher> duplicate() const = 0;
     bool search(const StorageDocument & doc);
     virtual void prepare(search::QueryTermList & qtl, const SharedSearcherBuf & buf);
     const FieldIdT & field()         const { return _field; }
@@ -133,7 +134,7 @@ public:
     static search::byte _wordChar[256];
 };
 
-typedef search::ObjectContainer<FieldSearcher> FieldSearcherContainer;
+typedef std::unique_ptr<FieldSearcher> FieldSearcherContainer;
 typedef std::vector<FieldSearcherContainer> FieldIdTSearcherMapT;
 
 class FieldIdTSearcherMap : public FieldIdTSearcherMapT
diff --git a/vsm/src/vespa/vsm/searcher/floatfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/floatfieldsearcher.cpp
index 0f31c6420be..41a07a03bf2 100644
--- a/vsm/src/vespa/vsm/searcher/floatfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/floatfieldsearcher.cpp
@@ -7,8 +7,17 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(FloatFieldSearcher);
-IMPLEMENT_DUPLICATE(DoubleFieldSearcher);
+std::unique_ptr<FieldSearcher>
+FloatFieldSearcher::duplicate() const
+{
+    return std::make_unique<FloatFieldSearcher>(*this);
+}
+
+std::unique_ptr<FieldSearcher>
+DoubleFieldSearcher::duplicate() const
+{
+    return std::make_unique<DoubleFieldSearcher>(*this);
+}
 
 template<typename T>
 FloatFieldSearcherT<T>::FloatFieldSearcherT(FieldIdT fId) :
diff --git a/vsm/src/vespa/vsm/searcher/floatfieldsearcher.h b/vsm/src/vespa/vsm/searcher/floatfieldsearcher.h
index a589706ff39..5f56ff67b30 100644
--- a/vsm/src/vespa/vsm/searcher/floatfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/floatfieldsearcher.h
@@ -38,14 +38,14 @@ typedef FloatFieldSearcherT<double> FloatFieldSearcherTD;
 class FloatFieldSearcher : public FloatFieldSearcherTF
 {
 public:
-    DUPLICATE(FloatFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     FloatFieldSearcher(FieldIdT fId=0) : FloatFieldSearcherTF(fId) { }
 };
 
 class DoubleFieldSearcher : public FloatFieldSearcherTD
 {
 public:
-    DUPLICATE(DoubleFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     DoubleFieldSearcher(FieldIdT fId=0) : FloatFieldSearcherTD(fId) { }
 };
 
diff --git a/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.cpp
index 335f6e81d23..e85cc20d418 100644
--- a/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.cpp
@@ -10,7 +10,11 @@ using search::v16qi;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(FUTF8StrChrFieldSearcher);
+std::unique_ptr<FieldSearcher>
+FUTF8StrChrFieldSearcher::duplicate() const
+{
+    return std::make_unique<FUTF8StrChrFieldSearcher>(*this);
+}
 
 FUTF8StrChrFieldSearcher::FUTF8StrChrFieldSearcher()
     : UTF8StrChrFieldSearcher(),
diff --git a/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.h b/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.h
index 265bca253d9..0539bdc6ea6 100644
--- a/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/futf8strchrfieldsearcher.h
@@ -8,7 +8,7 @@ namespace vsm {
 class FUTF8StrChrFieldSearcher : public UTF8StrChrFieldSearcher
 {
 public:
-    DUPLICATE(FUTF8StrChrFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     FUTF8StrChrFieldSearcher();
     FUTF8StrChrFieldSearcher(FieldIdT fId);
     ~FUTF8StrChrFieldSearcher();
diff --git a/vsm/src/vespa/vsm/searcher/intfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/intfieldsearcher.cpp
index 30d9992e2d4..5886a17cf4a 100644
--- a/vsm/src/vespa/vsm/searcher/intfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/intfieldsearcher.cpp
@@ -6,7 +6,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(IntFieldSearcher);
+std::unique_ptr<FieldSearcher>
+IntFieldSearcher::duplicate() const
+{
+    return std::make_unique<IntFieldSearcher>(*this);
+}
 
 IntFieldSearcher::IntFieldSearcher(FieldIdT fId) :
     FieldSearcher(fId),
diff --git a/vsm/src/vespa/vsm/searcher/intfieldsearcher.h b/vsm/src/vespa/vsm/searcher/intfieldsearcher.h
index 3e158b2d93c..ea190bf07cd 100644
--- a/vsm/src/vespa/vsm/searcher/intfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/intfieldsearcher.h
@@ -8,7 +8,7 @@ namespace vsm {
 class IntFieldSearcher : public FieldSearcher
 {
 public:
-    DUPLICATE(IntFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     IntFieldSearcher(FieldIdT fId=0);
     ~IntFieldSearcher();
     void prepare(search::QueryTermList & qtl, const SharedSearcherBuf & buf) override;
diff --git a/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.cpp
index 26c4021ac40..1de8c40c93a 100644
--- a/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.cpp
@@ -7,7 +7,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8ExactStringFieldSearcher);
+std::unique_ptr<FieldSearcher>
+UTF8ExactStringFieldSearcher::duplicate() const
+{
+    return std::make_unique<UTF8ExactStringFieldSearcher>(*this);
+}
 
 size_t
 UTF8ExactStringFieldSearcher::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.h b/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.h
index 9cca519d720..49557b8097d 100644
--- a/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/utf8exactstringfieldsearcher.h
@@ -16,7 +16,7 @@ protected:
     virtual size_t matchTerms(const FieldRef & f, const size_t shortestTerm) override;
 
 public:
-    DUPLICATE(UTF8ExactStringFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     UTF8ExactStringFieldSearcher()             : UTF8StringFieldSearcherBase() { }
     UTF8ExactStringFieldSearcher(FieldIdT fId) : UTF8StringFieldSearcherBase(fId) { }
 };
diff --git a/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.cpp
index b458b73be61..77708a682a2 100644
--- a/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.cpp
@@ -9,7 +9,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8FlexibleStringFieldSearcher);
+std::unique_ptr<FieldSearcher>
+UTF8FlexibleStringFieldSearcher::duplicate() const
+{
+    return std::make_unique<UTF8FlexibleStringFieldSearcher>(*this);
+}
 
 size_t
 UTF8FlexibleStringFieldSearcher::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.h b/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.h
index 0e58cae0938..f91bb48a068 100644
--- a/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/utf8flexiblestringfieldsearcher.h
@@ -26,7 +26,7 @@ private:
     virtual size_t matchTerms(const FieldRef & f, const size_t shortestTerm) override;
 
 public:
-    DUPLICATE(UTF8FlexibleStringFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     UTF8FlexibleStringFieldSearcher();
     UTF8FlexibleStringFieldSearcher(FieldIdT fId);
 };
diff --git a/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.cpp
index b54ed2c583d..fc78101737e 100644
--- a/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.cpp
@@ -7,7 +7,11 @@ using search::byte;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8StrChrFieldSearcher);
+std::unique_ptr<FieldSearcher>
+UTF8StrChrFieldSearcher::duplicate() const
+{
+    return std::make_unique<UTF8StrChrFieldSearcher>(*this);
+}
 
 size_t
 UTF8StrChrFieldSearcher::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.h b/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.h
index b109ede3e03..acfe1256ee5 100644
--- a/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/utf8strchrfieldsearcher.h
@@ -12,7 +12,7 @@ namespace vsm {
 class UTF8StrChrFieldSearcher : public UTF8StringFieldSearcherBase
 {
 public:
-    DUPLICATE(UTF8StrChrFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     UTF8StrChrFieldSearcher()             : UTF8StringFieldSearcherBase() { }
     UTF8StrChrFieldSearcher(FieldIdT fId) : UTF8StringFieldSearcherBase(fId) { }
 
diff --git a/vsm/src/vespa/vsm/searcher/utf8substringsearcher.cpp b/vsm/src/vespa/vsm/searcher/utf8substringsearcher.cpp
index 4b8c6e31927..8cda3e27bd5 100644
--- a/vsm/src/vespa/vsm/searcher/utf8substringsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8substringsearcher.cpp
@@ -8,7 +8,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8SubStringFieldSearcher);
+std::unique_ptr<FieldSearcher>
+UTF8SubStringFieldSearcher::duplicate() const
+{
+    return std::make_unique<UTF8SubStringFieldSearcher>(*this);
+}
 
 size_t
 UTF8SubStringFieldSearcher::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8substringsearcher.h b/vsm/src/vespa/vsm/searcher/utf8substringsearcher.h
index e034adeb1b5..9e01a56bdba 100644
--- a/vsm/src/vespa/vsm/searcher/utf8substringsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/utf8substringsearcher.h
@@ -11,7 +11,7 @@ namespace vsm {
 class UTF8SubStringFieldSearcher : public UTF8StringFieldSearcherBase
 {
 public:
-    DUPLICATE(UTF8SubStringFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     UTF8SubStringFieldSearcher()             : UTF8StringFieldSearcherBase() { }
     UTF8SubStringFieldSearcher(FieldIdT fId) : UTF8StringFieldSearcherBase(fId) { }
 protected:
diff --git a/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.cpp b/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.cpp
index eee88b34ea6..c19259273d0 100644
--- a/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.cpp
@@ -8,7 +8,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8SubstringSnippetModifier);
+std::unique_ptr<FieldSearcher>
+UTF8SubstringSnippetModifier::duplicate() const
+{
+    return std::make_unique<UTF8SubstringSnippetModifier>(*this);
+}
 
 size_t
 UTF8SubstringSnippetModifier::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.h b/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.h
index 3d266174f3d..fce0fdc2175 100644
--- a/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.h
+++ b/vsm/src/vespa/vsm/searcher/utf8substringsnippetmodifier.h
@@ -49,7 +49,7 @@ private:
 public:
     typedef std::shared_ptr<UTF8SubstringSnippetModifier> SP;
 
-    DUPLICATE(UTF8SubstringSnippetModifier);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
 
     UTF8SubstringSnippetModifier();
     UTF8SubstringSnippetModifier(FieldIdT fId);
diff --git a/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.cpp b/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.cpp
index 13074937185..1e9ec246743 100644
--- a/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.cpp
+++ b/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.cpp
@@ -7,7 +7,11 @@ using search::QueryTermList;
 
 namespace vsm {
 
-IMPLEMENT_DUPLICATE(UTF8SuffixStringFieldSearcher);
+std::unique_ptr<FieldSearcher>
+UTF8SuffixStringFieldSearcher::duplicate() const
+{
+    return std::make_unique<UTF8SuffixStringFieldSearcher>(*this);
+}
 
 size_t
 UTF8SuffixStringFieldSearcher::matchTerms(const FieldRef & f, const size_t mintsz)
diff --git a/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.h b/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.h
index 8bb32ab3c39..cc55ee7bb43 100644
--- a/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.h
+++ b/vsm/src/vespa/vsm/searcher/utf8suffixstringfieldsearcher.h
@@ -16,7 +16,7 @@ protected:
     virtual size_t matchTerms(const FieldRef & f, const size_t shortestTerm) override;
 
 public:
-    DUPLICATE(UTF8SuffixStringFieldSearcher);
+    std::unique_ptr<FieldSearcher> duplicate() const override;
     UTF8SuffixStringFieldSearcher()             : UTF8StringFieldSearcherBase() { }
     UTF8SuffixStringFieldSearcher(FieldIdT fId) : UTF8StringFieldSearcherBase(fId) { }
 };
diff --git a/vsm/src/vespa/vsm/vsm/fieldsearchspec.cpp b/vsm/src/vespa/vsm/vsm/fieldsearchspec.cpp
index 8d4cf72b824..8bb047beb24 100644
--- a/vsm/src/vespa/vsm/vsm/fieldsearchspec.cpp
+++ b/vsm/src/vespa/vsm/vsm/fieldsearchspec.cpp
@@ -52,6 +52,9 @@ FieldSearchSpec::FieldSearchSpec() :
 }
 FieldSearchSpec::~FieldSearchSpec() = default;
 
+FieldSearchSpec&
+FieldSearchSpec::operator=(FieldSearchSpec&& rhs) = default;
+
 FieldSearchSpec::FieldSearchSpec(const FieldIdT & fid, const vespalib::string & fname,
                                  VsmfieldsConfig::Fieldspec::Searchmethod searchDef,
                                  const vespalib::string & arg1, size_t maxLength_) :
@@ -72,36 +75,36 @@ FieldSearchSpec::FieldSearchSpec(const FieldIdT & fid, const vespalib::string &
     case VsmfieldsConfig::Fieldspec::Searchmethod::SSE2UTF8:
     case VsmfieldsConfig::Fieldspec::Searchmethod::UTF8:
         if (arg1 == "substring") {
-            _searcher = UTF8SubStringFieldSearcher(fid);
+            _searcher = std::make_unique<UTF8SubStringFieldSearcher>(fid);
         } else if (arg1 == "suffix") {
-            _searcher = UTF8SuffixStringFieldSearcher(fid);
+            _searcher = std::make_unique<UTF8SuffixStringFieldSearcher>(fid);
         } else if (arg1 == "exact") {
-            _searcher = UTF8ExactStringFieldSearcher(fid);
+            _searcher = std::make_unique<UTF8ExactStringFieldSearcher>(fid);
         } else if (arg1 == "word") {
-            _searcher = UTF8ExactStringFieldSearcher(fid);
+            _searcher = std::make_unique<UTF8ExactStringFieldSearcher>(fid);
         } else if (searchDef == VsmfieldsConfig::Fieldspec::Searchmethod::UTF8) {
-            _searcher = UTF8StrChrFieldSearcher(fid);
+            _searcher = std::make_unique<UTF8StrChrFieldSearcher>(fid);
         } else {
-            _searcher = FUTF8StrChrFieldSearcher(fid);
+            _searcher = std::make_unique<FUTF8StrChrFieldSearcher>(fid);
         }
         break;
     case VsmfieldsConfig::Fieldspec::Searchmethod::BOOL:
-        _searcher = BoolFieldSearcher(fid);
+        _searcher = std::make_unique<BoolFieldSearcher>(fid);
         break;
     case VsmfieldsConfig::Fieldspec::Searchmethod::INT8:
     case VsmfieldsConfig::Fieldspec::Searchmethod::INT16:
     case VsmfieldsConfig::Fieldspec::Searchmethod::INT32:
     case VsmfieldsConfig::Fieldspec::Searchmethod::INT64:
-        _searcher = IntFieldSearcher(fid);
+        _searcher = std::make_unique<IntFieldSearcher>(fid);
         break;
     case VsmfieldsConfig::Fieldspec::Searchmethod::FLOAT:
-        _searcher = FloatFieldSearcher(fid);
+        _searcher = std::make_unique<FloatFieldSearcher>(fid);
         break;
     case VsmfieldsConfig::Fieldspec::Searchmethod::DOUBLE:
-        _searcher = DoubleFieldSearcher(fid);
+        _searcher = std::make_unique<DoubleFieldSearcher>(fid);
         break;
     }
-    if (_searcher.valid()) {
+    if (_searcher) {
         setMatchType(_searcher, arg1);
         _searcher->maxFieldLength(maxLength());
     }
@@ -123,7 +126,7 @@ FieldSearchSpec::reconfig(const search::QueryTerm & term)
             (term.isExactstring() && _arg1 != "exact") ||
             (term.isPrefix() && _arg1 == "suffix"))
         {
-            _searcher = UTF8FlexibleStringFieldSearcher(id());
+            _searcher = std::make_unique<UTF8FlexibleStringFieldSearcher>(id());
             // preserve the basic match property of the searcher
             setMatchType(_searcher, _arg1);
             LOG(debug, "Reconfigured to use UTF8FlexibleStringFieldSearcher (%s) for field '%s' with id '%d'",
@@ -139,7 +142,7 @@ FieldSearchSpec::reconfig(const search::QueryTerm & term)
 vespalib::asciistream & operator <<(vespalib::asciistream & os, const FieldSearchSpec & f)
 {
     os << f._id << ' ' << f._name << ' ';
-    if ( ! f._searcher.valid()) {
+    if ( ! f._searcher) {
         os << " No searcher defined.\n";
     }
     return os;
@@ -251,7 +254,7 @@ bool FieldSearchSpecMap::buildFromConfig(const VsmfieldsHandle & conf)
         LOG(spam, "Parsing %s", cfs.name.c_str());
         FieldIdT fieldId = specMap().size();
         FieldSearchSpec fss(fieldId, cfs.name, cfs.searchmethod, cfs.arg1.c_str(), cfs.maxlength);
-        _specMap[fieldId] = fss;
+        _specMap[fieldId] = std::move(fss);
         _nameIdMap.add(cfs.name, fieldId);
         LOG(spam, "M in %d = %s", fieldId, cfs.name.c_str());
     }
@@ -298,7 +301,7 @@ void FieldSearchSpecMap::buildSearcherMap(const StringFieldIdTMapT & fieldsInQue
     for (const auto & entry : fieldsInQuery) {
         FieldIdT fId = entry.second;
         const FieldSearchSpec & spec = specMap().find(fId)->second;
-        fieldSearcherMap.push_back(spec.searcher());
+        fieldSearcherMap.emplace_back(spec.searcher().duplicate());
     }
     std::sort(fieldSearcherMap.begin(), fieldSearcherMap.end(), lesserField);
 }
diff --git a/vsm/src/vespa/vsm/vsm/fieldsearchspec.h b/vsm/src/vespa/vsm/vsm/fieldsearchspec.h
index 445334bd182..d3feb8621b5 100644
--- a/vsm/src/vespa/vsm/vsm/fieldsearchspec.h
+++ b/vsm/src/vespa/vsm/vsm/fieldsearchspec.h
@@ -14,10 +14,11 @@ public:
                     VsmfieldsConfig::Fieldspec::Searchmethod searchMethod,
                     const vespalib::string & arg1, size_t maxLength);
     ~FieldSearchSpec();
+    FieldSearchSpec& operator=(FieldSearchSpec&& rhs);
     const FieldSearcher & searcher() const { return *_searcher; }
     const vespalib::string &  name() const { return _name; }
     FieldIdT                    id() const { return _id; }
-    bool                     valid() const { return _searcher.valid(); }
+    bool                     valid() const { return static_cast<bool>(_searcher); }
     size_t               maxLength() const { return _maxLength; }
 
     /**