std::isfinite (3) - Linux Manuals

std::isfinite: std::isfinite

NAME

std::isfinite - std::isfinite

Synopsis

Defined in header <cmath>
bool isfinite( float arg ); (1) (since C++11)
bool isfinite( double arg ); (2) (since C++11)
bool isfinite( long double arg ); (3) (since C++11)
bool isfinite( IntegralType arg ); (4) (since C++11)

1-3) Determines if the given floating point number arg has finite value i.e. it is normal, subnormal or zero, but not infinite or NaN.
4) A set of overloads or a function template accepting the arg argument of any integral_type. Equivalent to (2) (the argument is cast to double).

Parameters

arg - floating point value

Return value

true if arg has finite value, false otherwise

Examples

// Run this code

  #include <iostream>
  #include <cmath>
  #include <cfloat>

  int main()
  {
      std::cout << std::boolalpha
                << "isfinite(NaN) = " << std::isfinite(NAN) << '\n'
                << "isfinite(Inf) = " << std::isfinite(INFINITY) << '\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(0.0) = true
  isfinite(exp(800)) = false
  isfinite(DBL_MIN/2.0) = true