std::is_arithmetic

< cpp‎ | types

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) or a cv-qualified version thereof, provides the member constant value equal to true. For any other type, value is false.

The behavior of a program that adds specializations for is_arithmetic or is_arithmetic_v (since C++17) is undefined.

Template parameters

a type to check

Helper variable template

template< class T > inline 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 built-in types for which the 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
        << "A:           " << std::is_arithmetic_v<A>           << '\n' // false
        << "bool:        " << std::is_arithmetic_v<bool>        << '\n' // true
        << "int:         " << std::is_arithmetic_v<int>         << '\n' // true
        << "int const:   " << std::is_arithmetic_v<int const>   << '\n' // true
        << "int &:       " << std::is_arithmetic_v<int&>        << '\n' // false
        << "int *:       " << std::is_arithmetic_v<int*>        << '\n' // false
        << "float:       " << std::is_arithmetic_v<float>       << '\n' // true
        << "float const: " << std::is_arithmetic_v<float const> << '\n' // true
        << "float &:     " << std::is_arithmetic_v<float&>      << '\n' // false
        << "float *:     " << std::is_arithmetic_v<float*>      << '\n' // false
        << "char:        " << std::is_arithmetic_v<char>        << '\n' // true
        << "char const:  " << std::is_arithmetic_v<char const>  << '\n' // true
        << "char &:      " << std::is_arithmetic_v<char&>       << '\n' // false
        << "char *:      " << std::is_arithmetic_v<char*>       << '\n' // false
        ;
}

Output:

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

is_integral (C++11)	checks if a type is an integral type (class template)
is_floating_point (C++11)	checks if a type is a floating-point type (class template)