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std::numeric_limits<T>::has_infinity

static const bool has_infinity;
(until C++11)
static constexpr bool has_infinity;
(since C++11)

The value of std::numeric_limits<T>::has_infinity is true for all types T capable of representing the positive infinity as a distinct special value. This constant is meaningful for all floating-point types and is guaranteed to be true if std::numeric_limits<T>::is_iec559 == true.

Standard specializations

T value of std::numeric_limits<T>::has_infinity
/* non-specialized */ false
bool false
char false
signed char false
unsigned char false
wchar_t false
char8_t (since C++20) false
char16_t (since C++11) false
char32_t (since C++11) false
short false
unsigned short false
int false
unsigned int false
long false
unsigned long false
long long (since C++11) false
unsigned long long (since C++11) false
float usually true
double usually true
long double usually true

Example

#include <iostream>
#include <limits>
 
int main()
{
    std::cout << std::boolalpha
              << std::numeric_limits<int>::has_infinity << '\n'
              << std::numeric_limits<long>::has_infinity << '\n'
              << std::numeric_limits<float>::has_infinity << '\n'
              << std::numeric_limits<double>::has_infinity << '\n';
}

Possible output:

false
false
true
true

See also

[static]
returns the positive infinity value of the given floating-point type
(public static member function)
[static]
identifies floating-point types that can represent the special value "quiet not-a-number" (NaN)
(public static member constant)
[static]
identifies floating-point types that can represent the special value "signaling not-a-number" (NaN)
(public static member constant)

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https://en.cppreference.com/w/cpp/types/numeric_limits/has_infinity