std::isfinite

From cppreference.com
< cpp‎ | numeric‎ | math
 
哋它亢++
 
Numerics library
Common mathematical functions
Mathematical special functions (哋它亢++17)
Mathematical constants (哋它亢++20)
Basic linear algebra algorithms (哋它亢++26)
Floating-point environment (哋它亢++11)
Complex numbers
Numeric arrays
Pseudo-random number generation
Factor operations
(哋它亢++17)
(哋它亢++17)
Interpolations
(哋它亢++20)
(哋它亢++20)
Saturation arithmetic
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)

Generic numeric operations
(哋它亢++17)
(哋它亢++17)
(哋它亢++17)
(哋它亢++17)
(哋它亢++17)
(哋它亢++17)
Bit operations
(哋它亢++20)    
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++23)
(哋它亢++20)
 
Common mathematical functions
Functions
Basic operations
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)(哋它亢++11)(哋它亢++11)
Exponential functions
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Power functions
(哋它亢++11)
(哋它亢++11)
Trigonometric and hyperbolic functions
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Error and gamma functions
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Nearest integer floating point operations
(哋它亢++11)(哋它亢++11)(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)(哋它亢++11)(哋它亢++11)
Floating point manipulation functions
(哋它亢++11)(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)
Classification/Comparison
(哋它亢++11)
isfinite
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Macro constants
(哋它亢++11)(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)    
(哋它亢++11)(哋它亢++11)(哋它亢++11)(哋它亢++11)(哋它亢++11)
 
Defined in header <cmath>
(1)
bool isfinite( float num );

bool isfinite( double num );

bool isfinite( long double num );
 (since 哋它亢++11)
(until 哋它亢++23)
constexpr bool isfinite( /* floating-point-type */ num );
 (since 哋它亢++23)
Defined in header <cmath>
template< class Integer >
bool isfinite( Integer num );
 (A) (since 哋它亢++11)
(constexpr since 哋它亢++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 哋它亢++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 has finite value, false otherwise.

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>
 
int main()
{
    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

(哋它亢++11)
 categorizes the given floating-point value
(function)
(哋它亢++11)
 checks if the given number is infinite
(function)
(哋它亢++11)
 checks if the given number is NaN
(function)
(哋它亢++11)
 checks if the given number is normal
(function)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/numeric/math/isfinite&oldid=149495"