std::is_floating_point - cppreference.com

From cppreference.com


`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.

Template parameters

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

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

#include <type_traits>

class A {};
static_assert(!std::is_floating_point_v<A>);

static_assert(std::is_floating_point_v<float>);
static_assert(!std::is_floating_point_v<float&>);
static_assert(std::is_floating_point_v<double>);
static_assert(!std::is_floating_point_v<double&>);
static_assert(!std::is_floating_point_v<int>);

int main() {}

	identifies the IEC 559/IEEE 754 floating-point types (public static member constant of `std::numeric_limits<T>`) [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]