NAME

std::max_align_t - std::max_align_t

Synopsis

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.

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.

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.

Example

// Run this code

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

Possible output:

16

References

* C++20 standard (ISO/IEC 14882:2020):

* 17.2.4 Sizes, alignments, and offsets [support.types.layout] (p:
507-508)

* C++17 standard (ISO/IEC 14882:2017):

* 21.2.4 Sizes, alignments, and offsets [support.types.layout] (p: 479)

* C++14 standard (ISO/IEC 14882:2014):

* 18.2 Types [support.types] (p: 443-444)

* C++11 standard (ISO/IEC 14882:2011):

* 18.2 Types [support.types] (p: 454-455)

See also

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