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

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

test/entt/common/throwing_allocator.hpp

@@ -0,0 +1,69 @@
+#ifndef ENTT_COMMON_THROWING_ALLOCATOR_HPP
+#define ENTT_COMMON_THROWING_ALLOCATOR_HPP
+
+#include <cstddef>
+#include <memory>
+#include <type_traits>
+
+namespace test {
+
+template<typename Type>
+class throwing_allocator: std::allocator<Type> {
+    template<typename Other>
+    friend class throwing_allocator;
+
+    using base = std::allocator<Type>;
+    struct test_exception {};
+
+public:
+    using value_type = Type;
+    using pointer = value_type *;
+    using const_pointer = const value_type *;
+    using void_pointer = void *;
+    using const_void_pointer = const void *;
+    using propagate_on_container_move_assignment = std::true_type;
+    using propagate_on_container_swap = std::true_type;
+    using exception_type = test_exception;
+
+    template<class Other>
+    struct rebind {
+        using other = throwing_allocator<Other>;
+    };
+
+    throwing_allocator() = default;
+
+    template<class Other>
+    throwing_allocator(const throwing_allocator<Other> &other)
+        : base{other} {}
+
+    pointer allocate(std::size_t length) {
+        if(trigger_on_allocate) {
+            trigger_on_allocate = false;
+            throw test_exception{};
+        }
+
+        trigger_on_allocate = trigger_after_allocate;
+        trigger_after_allocate = false;
+
+        return base::allocate(length);
+    }
+
+    void deallocate(pointer mem, std::size_t length) {
+        base::deallocate(mem, length);
+    }
+
+    bool operator==(const throwing_allocator<Type> &) const {
+        return true;
+    }
+
+    bool operator!=(const throwing_allocator<Type> &other) const {
+        return !(*this == other);
+    }
+
+    static inline bool trigger_on_allocate{};
+    static inline bool trigger_after_allocate{};
+};
+
+} // namespace test
+
+#endif