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

Defined in header
(1)
bool isfinite( float num ); bool isfinite( double num ); bool isfinite( long double num ); (since C++11) (until C++23)
constexpr bool isfinite( /*floating-point-type*/ num ); (since C++23)
SIMD overload (since C++26)
Defined in header
template< /*math-floating-point*/ V > constexpr typename /*deduced-simd-t*/<V>::mask_type isfinite ( const V& v_num ); (S) (since C++26)
Additional overloads
Defined in header
template< class Integer > bool isfinite( Integer num ); (A) (since C++11) (constexpr since C++23)
  1. Determines if the given floating point number num has finite value i.e. it is normal, subnormal or zero, but not infinite or NaN. The library provides overloads for all cv-unqualified floating-point types as the type of the parameter num.(since C++23)

A) Additional overloads are provided for all integer types, which are treated as double.

[edit] Parameters

num - floating-point or integer value
v_num - a data-parallel object of std::basic_simd specialization where its element type is a floating-point type

[edit] Return value

  1. true if num has finite value, false otherwise.

S) A data-parallel mask object where the ith element equals true if v_num[i] has finite value or false otherwise for all i in the range [​0​, v_num.size()).

[edit] Notes

The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::isfinite(num) has the same effect as std::isfinite(static_cast<double>(num)).

[edit] Examples

#include #include #include   int main() { std::cout << std::boolalpha << "isfinite(NaN) = " << std::isfinite(NAN) << '\n' << "isfinite(Inf) = " << std::isfinite(INFINITY) << '\n' << "isfinite(-Inf) = " << std::isfinite(-INFINITY) << '\n' << "isfinite(HUGE_VAL) = " << std::isfinite(HUGE_VAL) << '\n' << "isfinite(0.0) = " << std::isfinite(0.0) << '\n' << "isfinite(exp(800)) = " << std::isfinite(std::exp(800)) << '\n' << "isfinite(DBL_MIN/2.0) = " << std::isfinite(DBL_MIN / 2.0) << '\n'; }

Output:

isfinite(NaN) = false isfinite(Inf) = false isfinite(-Inf) = false isfinite(HUGE_VAL) = false isfinite(0.0) = true isfinite(exp(800)) = false isfinite(DBL_MIN/2.0) = true

[edit] See also