std::is_floating_point - cppreference.com (original) (raw)

| | | | | ------------------------------------------------ | | ------------- | | template< class T > struct is_floating_point; | | (since C++11) |

std::is_floating_point is a 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.

If the program adds specializations for std::is_floating_point or std::is_floating_point_v, the behavior is undefined.

Contents

• 1 Template parameters
• 2 Helper variable template
• 3 Inherited from std::integral_constant
  • 3.1 Member constants
  • 3.2 Member functions
  • 3.3 Member types
  • 3.4 Possible implementation
  • 3.5 Example
  • 3.6 See also

[edit] Template parameters

[edit] Helper variable template

| template< class T > constexpr bool is_floating_point_v = is_floating_point<T>::value; | | (since C++17) | | --------------------------------------------------------------------------------------------- | | ------------- |

Inherited from std::integral_constant

Member constants

| | true if T is a floating-point type (possibly cv-qualified), false otherwise (public static member constant) | | -------------------------------------------------------------------------------------------------------------- |

Member functions

| | converts the object to bool, returns value (public member function) | | ---------------------------------------------------------------------- | | | returns value (public member function) |

Member types

[edit] Possible implementation

template struct is_floating_point : std::integral_constant< bool, // Note: standard floating-point types std::is_same<float, typename std::remove_cv::type>::value || std::is_same<double, typename std::remove_cv::type>::value || std::is_same<long double, typename std::remove_cv::type>::value // Note: extended floating-point types (C++23, if supported) || std::is_same<std::float16_t, typename std::remove_cv::type>::value || std::is_same<std::float32_t, typename std::remove_cv::type>::value || std::is_same<std::float64_t, typename std::remove_cv::type>::value || std::is_same<std::float128_t, typename std::remove_cv::type>::value || std::is_same<std::bfloat16_t, typename std::remove_cv::type>::value > {};

[edit] Example

#include   class A {}; static_assert(!std::is_floating_point_v);   static_assert(std::is_floating_point_v); static_assert(!std::is_floating_point_v<float&>); static_assert(std::is_floating_point_v); static_assert(!std::is_floating_point_v<double&>); static_assert(!std::is_floating_point_v);   int main() {}

[edit] See also

| | identifies the IEC 559/IEEE 754 floating-point types (public static member constant of std::numeric_limits) [edit] | | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | checks if a type is an integral type (class template) [edit] | | | checks if a type is an arithmetic type (class template) [edit] | | | specifies that a type is a floating-point type (concept) [edit] |