std::max_align_t is a standard-layout TrivialType(until C++26)TriviallyCopyable type(since C++26) whose alignment requirement is at least as strict (as large) as that of every scalar type.

std::is_trivially_default_constructible_v<std::max_align_t> is true.

Notes

Pointers returned by allocation functions such as std::malloc are suitably aligned for any object, which means they are aligned at least as strictly as std::max_align_t.

Example

#include <cstddef>
#include <iostream>

int main()
{
    std::cout << alignof(std::max_align_t) << '\n';
}

References