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 true
. For any other type, value
is false
.
T | - | a type to check |
template< class T > inline constexpr bool is_arithmetic_v = is_arithmetic<T>::value; | (since C++17) |
value
[static] | true if T is an arithmetic type , false otherwise (public static member constant) |
operator bool | converts the object to bool , returns value (public member function) |
operator()
(C++14) | returns value (public member function) |
Type | Definition |
---|---|
value_type | bool |
type | std::integral_constant<bool, value> |
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.
template< class T > struct is_arithmetic : std::integral_constant<bool, std::is_integral<T>::value || std::is_floating_point<T>::value> {}; |
#include <iostream> #include <type_traits> class A {}; int main() { std::cout << std::boolalpha; std::cout << "A: " << std::is_arithmetic<A>::value << '\n'; std::cout << "bool: " << std::is_arithmetic<bool>::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'; std::cout << "char: " << std::is_arithmetic<char>::value << '\n'; std::cout << "char const: " << std::is_arithmetic<char const>::value << '\n'; std::cout << "char &: " << std::is_arithmetic<char&>::value << '\n'; std::cout << "char *: " << std::is_arithmetic<char*>::value << '\n'; }
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
(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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