Merge pull request #24079 from vespa-engine/havardpe/start-using-concepts

start using concepts in vespalib

5 files changed, 22 insertions, 19 deletions

diff --git a/vespalib/src/tests/simple_thread_bundle/simple_thread_bundle_test.cpp b/vespalib/src/tests/simple_thread_bundle/simple_thread_bundle_test.cpp
index d6e0e473e59..27e75315dfc 100644
--- a/vespalib/src/tests/simple_thread_bundle/simple_thread_bundle_test.cpp
+++ b/vespalib/src/tests/simple_thread_bundle/simple_thread_bundle_test.cpp
@@ -249,6 +249,9 @@ TEST_FF("require that various versions of run can be used to invoke targets", Si
     f2.check({4,4,4,4,4});
     f1.run(f2.cnts);
     f2.check({5,5,5,5,5});
+    std::initializer_list<std::reference_wrapper<Cnt>> list = {f2.cnts[0], f2.cnts[1], f2.cnts[2], f2.cnts[3], f2.cnts[4]};
+    f1.run(list);
+    f2.check({6,6,6,6,6});
 }
 
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/vespalib/src/vespa/vespalib/util/rendezvous.h b/vespalib/src/vespa/vespalib/util/rendezvous.h
index 6121b3f3dd6..2880f325d96 100644
--- a/vespalib/src/vespa/vespalib/util/rendezvous.h
+++ b/vespalib/src/vespa/vespalib/util/rendezvous.h
@@ -93,8 +93,7 @@ public:
      * @return output parameter for a single thread
      * @param input input parameter for a single thread
      **/
-    template <bool ext_id = external_id>
-    typename std::enable_if<!ext_id,OUT>::type rendezvous(IN input);
+    OUT rendezvous(IN input) requires (!external_id);
 
     /**
      * Called by individual threads to synchronize execution and share
@@ -107,8 +106,7 @@ public:
      * @param my_id participant id for this thread (must be in range and
      *              not conflicting with other threads)
      **/
-    template <bool ext_id = external_id>
-    typename std::enable_if<ext_id,OUT>::type rendezvous(IN input, size_t my_id);
+    OUT rendezvous(IN input, size_t my_id) requires (external_id);
 };
 
 } // namespace vespalib
diff --git a/vespalib/src/vespa/vespalib/util/rendezvous.hpp b/vespalib/src/vespa/vespalib/util/rendezvous.hpp
index a22e05fac3f..4b3c6138428 100644
--- a/vespalib/src/vespa/vespalib/util/rendezvous.hpp
+++ b/vespalib/src/vespa/vespalib/util/rendezvous.hpp
@@ -59,12 +59,12 @@ template <typename IN, typename OUT, bool external_id>
 Rendezvous<IN, OUT, external_id>::~Rendezvous() = default;
 
 template <typename IN, typename OUT, bool external_id>
-template <bool ext_id>
-typename std::enable_if<!ext_id,OUT>::type
+OUT
 Rendezvous<IN, OUT, external_id>::rendezvous(IN input)
+    requires (!external_id)
 {
     OUT ret{};
-    static_assert(ext_id == external_id);
+    static_assert(!external_id);
     if (_size == 1) {
         meet_self(input, ret);
     } else {
@@ -75,13 +75,13 @@ Rendezvous<IN, OUT, external_id>::rendezvous(IN input)
 }
 
 template <typename IN, typename OUT, bool external_id>
-template <bool ext_id>
-typename std::enable_if<ext_id,OUT>::type
+OUT
 Rendezvous<IN, OUT, external_id>::rendezvous(IN input, size_t my_id)
+    requires (external_id)
 {
     OUT ret{};
     assert(my_id < _size);
-    static_assert(ext_id == external_id);
+    static_assert(external_id);
     if (_size == 1) {
         meet_self(input, ret);
     } else {
diff --git a/vespalib/src/vespa/vespalib/util/small_vector.h b/vespalib/src/vespa/vespalib/util/small_vector.h
index cf9910e24b5..3e0e3cc7e4b 100644
--- a/vespalib/src/vespa/vespalib/util/small_vector.h
+++ b/vespalib/src/vespa/vespalib/util/small_vector.h
@@ -104,15 +104,15 @@ private:
             free(old_data);
         }
     }
-    template <typename InputIt>
-    void init(InputIt first, InputIt last, std::random_access_iterator_tag) {
+    template <std::random_access_iterator InputIt>
+    void init(InputIt first, InputIt last) {
         reserve(last - first);
         while (first != last) {
             small_vector::create_at((_data + _size++), *first++);
         }
     }
-    template <typename InputIt>
-    void init(InputIt first, InputIt last, std::input_iterator_tag) {
+    template <std::input_iterator InputIt>
+    void init(InputIt first, InputIt last) {
         while (first != last) {
             emplace_back(*first++);
         }
@@ -137,10 +137,10 @@ public:
             small_vector::create_at((_data + _size++), value);
         }
     }
-    template <typename InputIt, std::enable_if_t<std::is_base_of_v<std::input_iterator_tag, typename std::iterator_traits<InputIt>::iterator_category>, bool> = true>
+    template <std::input_iterator InputIt>
     SmallVector(InputIt first, InputIt last) : SmallVector()
     {
-        init(first, last, typename std::iterator_traits<InputIt>::iterator_category());
+        init(first, last);
     }
     SmallVector(SmallVector &&rhs) : SmallVector() {
         reserve(rhs._size);
diff --git a/vespalib/src/vespa/vespalib/util/thread_bundle.h b/vespalib/src/vespa/vespalib/util/thread_bundle.h
index 830d7c76e7c..cfdedb347c8 100644
--- a/vespalib/src/vespa/vespalib/util/thread_bundle.h
+++ b/vespalib/src/vespa/vespalib/util/thread_bundle.h
@@ -4,6 +4,7 @@
 
 #include "runnable.h"
 #include <vector>
+#include <ranges>
 
 namespace vespalib {
 
@@ -46,10 +47,11 @@ struct ThreadBundle {
     }
 
     // convenience run wrapper
-    template <typename Item>
-    std::enable_if_t<!is_runnable_ptr<Item>(),void> run(std::vector<Item> &items) {
+    template <std::ranges::range List>
+    requires (!is_runnable_ptr<std::ranges::range_value_t<List>>())
+    void run(List &items) {
         std::vector<Runnable*> targets;
-        targets.reserve(items.size());
+        targets.reserve(std::ranges::size(items));
         for (auto &item: items) {
             targets.push_back(resolve(item));
         }