Defined in header <cstddef>
typedef /*implementation-defined*/ max_align_t;
(since C++11)

std::max_align_t is a trivial standard-layout type whose alignment requirement is at least as strict (as large) as that of every scalar type.


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.

std::max_align_t is usually synonymous with the largest scalar type, which is long double on most platforms, and its alignment requirement is either 8 or 16.


#include <iostream>
#include <cstddef>
int main()
    std::cout << alignof(std::max_align_t) << '\n';

Possible output:


See also

alignof operator queries alignment requirements of a type (since C++11)
obtains the type's alignment requirements
(class template)
checks if a type is a scalar type
(class template)

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