Queries alignment requirements of a type.

[edit]Syntax

Returns a value of typestd::size_t.

[edit]Explanation

Returnsthe alignment, in bytes, required for any instance of the type indicated bytype-id, which is eithercomplete object type, an array type whose element type is complete, or a reference type to one of those types.

If the type is reference type, the operator returns the alignment of referenced type; if the type is array type, alignment requirement of the element type is returned.

[edit]Notes

Seealignment for the meaning and properties of the value returned byalignof.

[edit]Keywords

alignof

[edit]Example

#include <iostream> struct Foo{int   i;float f;char  c;}; // Note: alignas(alignof(long double)) below can be// simplified to alignas(long double) if desired.struct alignas(alignof(longdouble)) Foo2{// put your definition here};  struct Empty{}; struct alignas(64) Empty64{}; #define SHOW(expr) std::cout << #expr << " = " << (expr) << '\n' int main(){    SHOW(alignof(char));    SHOW(alignof(int*));    SHOW(alignof(Foo));    SHOW(alignof(Foo2));    SHOW(alignof(Empty));    SHOW(alignof(Empty64));}

alignof(char) = 1alignof(int*) = 8alignof(Foo) = 4alignof(Foo2) = 16alignof(Empty) = 1alignof(Empty64) = 64

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit]References

[edit]See also

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