Does std::allocator handle over-aligned types in C++17?

问题

C++17 introduces std::aligned_alloc and alignment-aware new that can do over-aligned allocations, but what about std::allocator? Does it handle over-aligned types?

回答1:

In N4659(C++17 DIS), 23.10.9.1 [allocator.members], bullet 2

T* allocate(size_t n);

Returns: A pointer to the initial element of an array of storage of size n * sizeof(T), aligned appropriately for objects of type T.

Compared to C++14, the sentence

It is implementation-defined whether over-aligned types are supported

has been removed. So std::allocator should support over-aligned types in C++17.

来源：https://stackoverflow.com/questions/46399544/does-stdallocator-handle-over-aligned-types-in-c17