std::aligned_storage - Man Page

struct std::aligned_storage< _Len, _Align >"Alignment type.

The value of _Align is a default-alignment which shall be the most stringent alignment requirement for any C++ object type whose size is no greater than _Len (3.9). The member typedef type shall be a POD type suitable for use as uninitialized storage for any object whose size is at most _Len and whose alignment is a divisor of _Align.

Deprecated

Deprecated in C++23. Uses can be replaced by an array std::byte[_Len] declared with alignas(_Align).