Defined in header <cmath> | ||
|---|---|---|
| (1) | ||
bool isinf( float num ); bool isinf( double num ); bool isinf( long double num ); | (since C++11) (until C++23) | |
constexpr bool isinf( /* floating-point-type */ num ); | (since C++23) | |
| Additional overloads | ||
Defined in header <cmath> | ||
template< class Integer > bool isinf( Integer num ); | (A) | (since C++11) (constexpr since C++23) |
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)
double
| num | - | floating-point or integer value |
true if num is infinite, false otherwise.
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::isinf(num) has the same effect as std::isinf(static_cast<double>(num)).
#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
|
(C++11) | categorizes the given floating-point value (function) |
|
(C++11) | checks if the given number has finite value (function) |
|
(C++11) | checks if the given number is NaN (function) |
|
(C++11) | checks if the given number is normal (function) |
C documentation for isinf |
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