It is used to find the member constant value equal to the alignment requirement of the type T. If T is a reference type than it returns the alignment requirements of the type referred to. If T is an array type than it returns the alignment requirements of the element type.
template <class T> struct alignment_of;
Parameter: The template std::alignment_of accepts a single parameter T (Trait class).
Below programs illustrate the std::alignment_of template in C++ STL:
1 4 8
1 4 1