From cppreference.com
Defined in header
boolisfinite(floatnum);boolisfinite(doublenum);boolisfinite(longdoublenum); (1)(since C++11)
(until C++23)constexprboolisfinite(/*floating-point-type*/num);(since C++23)
(since C++26)
Defined in header
template</*math-floating-point*/V>constexprtypename/*deduced-simd-t*/<V>::mask_typeisfinite(constV&v_num); (S) (since C++26)
Defined in header
template<classInteger>boolisfinite(Integernum); (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.
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 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()).
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)).
Examples
Run this code
#include<cfloat>#include<cmath>#include<iostream>intmain(){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 See also