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) 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
| T | - | 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
See also
|
(C++11)
|
checks if a type is an integral type (class template) |
|
(C++11)
|
checks if a type is a floating-point type (class template) |
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https://en.cppreference.com/w/cpp/types/is_arithmetic
