std::is_sufficiently_aligned

 

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Defined in header <memory>
template< std::size_t N, class T > bool is_sufficiently_aligned( T* ptr );		(since C++26)

Checks whether the pointer ptr points to an object whose alignment has a value of at least N.

The behavior is undefined if ptr does not point to an object of type T (ignoring cv-qualification at every level).

Return value

true if ptr points to an object that has alignment at least N; otherwise false.

Exceptions

Throws nothing.

Notes

std::is_sufficiently_aligned can be used as a precondition to std::assume_aligned.

Feature-test macro	Value	Std	Feature
__cpp_lib_is_sufficiently_aligned	202411L	(C++26)	std::is_sufficiently_aligned

Possible implementation

template<std::size_t N, class T> bool is_sufficiently_aligned(T* ptr) { return std::bit_cast<std::uintptr_t>(ptr) % N == 0; }

See also

alignof (C++11)	queries alignment requirements of a type (operator)
alignas (C++11)	specifies that the storage for the variable should be aligned by specific amount (specifier)
aligned_storage (since C++11)(deprecated in C++23)	defines the type suitable for use as uninitialized storage for types of given size (class template)
align (C++11)	aligns a pointer in a buffer (function)
aligned_accessor (C++26)	a type for aligned access to elements of mdspan (class template)