std::is_floating_point
Defined in header <type_traits> | ||
|---|---|---|
template< class T > struct is_floating_point; | (since C++11) |
Checks whether T is a floating-point type. Provides the member constant value which is equal to true, if T is the type float, double, long double, including any cv-qualified variants. Otherwise, value is equal to false.
Template parameters
| T | - | a type to check |
Helper variable template
template< class T > inline constexpr bool is_floating_point_v = is_floating_point<T>::value; | (since C++17) |
Inherited from std::integral_constant
Member constants
| value
[static] | true if T is a floating-point type (possibly cv-qualified) , 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> |
Possible implementation
template< class T >
struct is_floating_point
: std::integral_constant<
bool,
std::is_same<float, typename std::remove_cv<T>::type>::value ||
std::is_same<double, typename std::remove_cv<T>::type>::value ||
std::is_same<long double, typename std::remove_cv<T>::type>::value
> {}; |
Example
#include <iostream>
#include <type_traits>
class A {};
int main()
{
std::cout << std::boolalpha;
std::cout << std::is_floating_point<A>::value << '\n';
std::cout << std::is_floating_point<float>::value << '\n';
std::cout << std::is_floating_point<int>::value << '\n';
}Output:
false true false
See also
|
[static] | identifies the IEC 559/IEEE 754 floating-point types (public static member constant of std::numeric_limits<T>) |
|
(C++11) | checks if a type is an integral type (class template) |
|
(C++11) | checks if a type is an arithmetic type (class template) |
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