Squashed 'external/entt/entt/' content from commit fef92113

git-subtree-dir: external/entt/entt
git-subtree-split: fef921132cae7588213d0f9bcd2fb9c8ffd8b7fc

test/entt/common/tracked_memory_resource.hpp

@@ -0,0 +1,64 @@
+#ifndef ENTT_COMMON_TRACKED_MEMORY_RESOURCE_HPP
+#define ENTT_COMMON_TRACKED_MEMORY_RESOURCE_HPP
+
+#ifdef ENTT_HAS_HEADER_VERSION
+#    include <version>
+#
+#    if defined(__cpp_lib_memory_resource) && __cpp_lib_memory_resource >= 201603L
+#        define ENTT_HAS_TRACKED_MEMORY_RESOURCE
+#
+#        include <cstddef>
+#        include <memory_resource>
+#        include <string>
+
+namespace test {
+
+class tracked_memory_resource: public std::pmr::memory_resource {
+    void *do_allocate(std::size_t bytes, std::size_t alignment) override {
+        ++alloc_counter;
+        return std::pmr::get_default_resource()->allocate(bytes, alignment);
+    }
+
+    void do_deallocate(void *value, std::size_t bytes, std::size_t alignment) override {
+        ++dealloc_counter;
+        std::pmr::get_default_resource()->deallocate(value, bytes, alignment);
+    }
+
+    bool do_is_equal(const std::pmr::memory_resource &other) const noexcept override {
+        return (this == &other);
+    }
+
+public:
+    using string_type = std::pmr::string;
+    using size_type = std::size_t;
+
+    static constexpr const char *default_value = "a string long enough to force an allocation (hopefully)";
+
+    tracked_memory_resource()
+        : alloc_counter{},
+          dealloc_counter{} {}
+
+    size_type do_allocate_counter() const noexcept {
+        return alloc_counter;
+    }
+
+    size_type do_deallocate_counter() const noexcept {
+        return dealloc_counter;
+    }
+
+    void reset() noexcept {
+        alloc_counter = 0u;
+        dealloc_counter = 0u;
+    }
+
+private:
+    size_type alloc_counter;
+    size_type dealloc_counter;
+};
+
+} // namespace test
+
+#    endif
+#endif
+
+#endif