# std::is_floating_point

From cppreference.com
< cpp‎ | types

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

`std::is_floating_point` is an UnaryTypeTrait.

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, or any extended floating-point types (`std::float16_t`, `std::float32_t`, `std::float64_t`, `std::float128_t`, or `std::bfloat16_t`) (since C++23), including any cv-qualified variants. Otherwise, `value` is equal to false.

The behavior of a program that adds specializations for `std::is_floating_point` or `std::is_floating_point_v` (since C++17) is undefined.

### 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,
             // Note: standard floating-point types
             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
             // Note: extended floating-point types (C++23, if supported)
             || std::is_same<std::float16_t, typename std::remove_cv<T>::type>::value
             || std::is_same<std::float32_t, typename std::remove_cv<T>::type>::value
             || std::is_same<std::float64_t, typename std::remove_cv<T>::type>::value
             || std::is_same<std::float128_t, typename std::remove_cv<T>::type>::value
             || std::is_same<std::bfloat16_t, typename std::remove_cv<T>::type>::value
         > {};

### Example

Run this code

    #include <iostream>
    #include <type_traits>

    class A {};

    int main()
    {
        std::cout << std::boolalpha;
        std::cout << "      A: " << std::is_floating_point<A>::value << '\n';
        std::cout << "  float: " << std::is_floating_point<float>::value << '\n';
        std::cout << " float&: " << std::is_floating_point<float&>::value << '\n';
        std::cout << " double: " << std::is_floating_point<double>::value << '\n';
        std::cout << "double&: " << std::is_floating_point<double&>::value << '\n';
        std::cout << "    int: " << std::is_floating_point<int>::value << '\n';
    }

Output:

          A: false
      float: true
     float&: false
     double: true
    double&: false
        int: false

### See also

is_iec559 [static] | identifies the IEC 559/IEEE 754 floating-point types (public static member constant of `std::numeric_limits<T>`)
is_integral (C++11) | checks if a type is an integral type (class template)
is_arithmetic (C++11) | checks if a type is an arithmetic type (class template)
floating_point (C++20) | specifies that a type is a floating-point type (concept)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/types/is_floating_point&oldid=152437"