std::is_arithmetic

Defined in header <type_traits>
template< class T >
struct is_arithmetic;
(since C++11)

If T is an arithmetic type (that is, an integral type or a floating-point type), provides the member constant value equal true. For any other type, value is false.

Template parameters

T - a type to check

Helper variable template

template< class T >
constexpr bool is_arithmetic_v = is_arithmetic<T>::value;
(since C++17)

Inherited from std::integral_constant

Member constants

value
[static]
true if T is an arithmetic type , false otherwise
(public static member constant)

Member functions

operator bool
converts the object to bool, returns value
(public member function)
operator()
(C++14)
returns value
(public member function)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>

Notes

Arithmetic types are the types for which the built-in arithmetic operators (+, -, *, /) are defined (possibly in combination with the usual arithmetic conversions).

Specializations of std::numeric_limits are provided for all arithmetic types.

Possible implementation

template< class T >
struct is_arithmetic : std::integral_constant<bool,
                                              std::is_integral<T>::value ||
                                              std::is_floating_point<T>::value> {};

Example

#include <iostream>
#include <type_traits>
 
class A {};
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << "A:           " <<  std::is_arithmetic<A>::value << '\n';
    std::cout << "int:         " <<  std::is_arithmetic<int>::value << '\n';
    std::cout << "int const:   " <<  std::is_arithmetic<int const>::value << '\n';
    std::cout << "int &:       " <<  std::is_arithmetic<int&>::value << '\n';
    std::cout << "int *:       " <<  std::is_arithmetic<int*>::value << '\n';
    std::cout << "float:       " <<  std::is_arithmetic<float>::value << '\n';
    std::cout << "float const: " <<  std::is_arithmetic<float const>::value << '\n';
    std::cout << "float &:     " <<  std::is_arithmetic<float&>::value << '\n';
    std::cout << "float *:     " <<  std::is_arithmetic<float*>::value << '\n';
}

Output:

A:           false
int:         true
int const:   true
int &:       false
int *:       false
float:       true
float const: true
float &:     false
float *:     false

See also

(C++11)
checks if a type is integral type
(class template)
checks if a type is floating-point type
(class template)
std::experimental::is_arithmetic_v
(library fundamentals TS)
variable template alias of std::is_arithmetic::value
(variable template)
doc_CPP
2016-10-11 10:03:53
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