NAME

std::isnormal - std::isnormal

Synopsis

Defined in header <cmath>
bool isnormal( float arg ); (1) (since C++11)
(constexpr since C++23)
bool isnormal( double arg ); (2) (since C++11)
(constexpr since C++23)
bool isnormal( long double arg ); (3) (since C++11)
(constexpr since C++23)
bool isnormal( IntegralType arg ); (4) (since C++11)
(constexpr since C++23)

1-3) Determines if the given floating point number arg is normal, i.e. is neither
zero, subnormal, infinite, nor 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 is normal, false otherwise

Example

// Run this code

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

int main()
{
std::cout << std::boolalpha
<< "isnormal(NaN) = " << std::isnormal(NAN) << '\n'
<< "isnormal(Inf) = " << std::isnormal(INFINITY) << '\n'
<< "isnormal(0.0) = " << std::isnormal(0.0) << '\n'
<< "isnormal(DBL_MIN/2.0) = " << std::isnormal(DBL_MIN/2.0) << '\n'
<< "isnormal(1.0) = " << std::isnormal(1.0) << '\n';
}

Output:

isnormal(NaN) = false
isnormal(Inf) = false
isnormal(0.0) = false
isnormal(DBL_MIN/2.0) = false
isnormal(1.0) = true

See also

fpclassify categorizes the given floating-point value
(C++11) (function)
isfinite checks if the given number has finite value
(C++11) (function)
isinf checks if the given number is infinite
(C++11) (function)
isnan checks if the given number is NaN
(C++11) (function)