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std::isinf(3) C++ Standard Libary std::isinf(3) NAME std::isinf - std::isinf Synopsis Defined in header <cmath> bool isinf( float num ); (since C++11) bool isinf( double num ); (until C++23) bool isinf( long double num ); constexpr bool isinf( /* floating-point-type */ num (1) (since C++23) ); Additional overloads Defined in header <cmath> template< class Integer > (A) (since C++11) bool isinf( Integer num ); (const- expr since C++23) 1) Determines if the given floating-point number num is a positive or negative infinity. 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 Return value true if num is infinite, false otherwise. Notes GCC and Clang support a -ffinite-math option (additionally implied by -ffast-math), which allows the respective compiler to assume the nonexistence of special IEEE-754 floating point values such as NaN, infinity, or negative zero. In other words, std::isinf is assumed to always return false under this option. 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 inte- ger type, std::isinf(num) has the same effect as std::isinf(static_cast<dou- ble>(num)). Example // Run this code #include <cfloat> #include <cmath> #include <iostream> #include <limits> int main() { const double max = std::numeric_limits<double>::max(); const double inf = std::numeric_limits<double>::infinity(); std::cout << std::boolalpha << "isinf(NaN) = " << std::isinf(NAN) << '\n' << "isinf(Inf) = " << std::isinf(INFINITY) << '\n' << "isinf(max) = " << std::isinf(max) << '\n' << "isinf(inf) = " << std::isinf(inf) << '\n' << "isinf(0.0) = " << std::isinf(0.0) << '\n' << "isinf(exp(800)) = " << std::isinf(std::exp(800)) << '\n' << "isinf(DBL_MIN/2.0) = " << std::isinf(DBL_MIN / 2.0) << '\n'; } Output: isinf(NaN) = false isinf(Inf) = true isinf(max) = false isinf(inf) = true isinf(0.0) = false isinf(exp(800)) = true isinf(DBL_MIN/2.0) = false See also fpclassify categorizes the given floating-point value (C++11) (function) isfinite checks if the given number has finite value (C++11) (function) isnan checks if the given number is NaN (C++11) (function) isnormal checks if the given number is normal (C++11) (function) C documentation for isinf http://cppreference.com 2024.06.10 std::isinf(3)
NAME | Synopsis | Parameters | Return value | Notes | Example | Output: | See also
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