std::uninitialized_construct_using_allocator

 

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在标头 <memory> 定义
template< class T, class Alloc, class... Args > constexpr T* uninitialized_construct_using_allocator( T* p, const Alloc& alloc, Args&&... args );		(C++20 起)

以使用分配器构造的手段在 p 所指示的未初始化内存位置创建给定类型 T 的对象。

等价于

return std::apply([&]<class... Xs>(Xs&&...xs) {
        return std::construct_at(p, std::forward<Xs>(xs)...);
    }, std::uses_allocator_construction_args<T>(alloc, std::forward<Args>(args)...));

参数

p	-	将要放置对象的内存位置。
alloc	-	要使用的分配器。
args	-	传递给 T 构造函数的参数。

返回值

指向新创建的 T 类型对象的指针。

异常

可能抛出 T 的构造函数所抛的任何异常，常包括 std::bad_alloc 。

参阅

uses_allocator (C++11)	检查指定的类型是否支持使用分配器的构造 (类模板)
make_obj_using_allocator (C++20)	以使用分配器构造的手段创建给类型的对象 (函数模板)