C++

Reference

<type_traits>

class template
<type_traits>

std::alignment_of

template <class T> struct alignment_of;
Alignment of

Trait class to obtain the alignment requirement of type T.

If T is a reference type, the alignment obtained is the one required by the referenced type.

If T is an array type, the alignment obtained is the one required by the element type.

The class behaves as if defined as:
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template<class T> struct alignment_of : integral_constant <size_t,alignof(T)> {};

Template parameters

T
A complete object type, or an array thereof, or a reference to a complete object type.

Member types

Inherited from integral_constant:
member typedefinition
value_typesize_t
typeintegral_constant<size_t,alignof(T)>

Member constants

Inherited from integral_constant:
member constantdefinition
valuealignof(T)

Member functions

Inherited from integral_constant:
operator size_t
Returns value (public member function)

Example

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// alignment_of example
#include <iostream>
#include <type_traits>

int main() {
  std::cout << "alignment_of:" << std::endl;
  std::cout << "char: " << std::alignment_of<char>::value << std::endl;
  std::cout << "int: " << std::alignment_of<int>::value << std::endl;
  std::cout << "int[20]: " << std::alignment_of<int[20]>::value << std::endl;
  std::cout << "long long int: " << std::alignment_of<long long int>::value << std::endl;
  return 0;
}

Possible output:
alignment_of
char: 1
int: 4
int[20]: 4
long long int: 8


See also

rank
Array rank (class template)
extent
Array dimension extent (class template)