Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
Three-way comparison
General utilities
Date and time
Function objects
Formatting library (C++20)
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types
Elementary string conversions

static T infinity() throw();
(until C++11)
static constexpr T infinity() noexcept;
(since C++11)

Returns the special value "positive infinity", as represented by the floating-point type T. Only meaningful if std::numeric_limits<T>::has_infinity == true. In IEEE 754, the most common binary representation of floating-point numbers, the positive infinity is the value with all bits of the exponent set and all bits of the fraction cleared.

[edit] Return value

T std::numeric_limits<T>::infinity()
/* non-specialized */ T()
bool false
char 0
signed char 0
unsigned char 0
wchar_t 0
char8_t (since C++20) 0
char16_t (since C++11) 0
char32_t (since C++11) 0
short 0
unsigned short 0
int 0
unsigned int 0
long 0
unsigned long 0
long long (since C++11) 0
unsigned long long (since C++11) 0
double HUGE_VAL
long double HUGE_VALL

[edit] Example

#include <iostream>
#include <limits>
int main()
    double max = std::numeric_limits<double>::max();
    double inf = std::numeric_limits<double>::infinity();
    if (inf > max)
        std::cout << inf << " is greater than " << max << '\n';


inf is greater than 1.79769e+308

[edit] See also

identifies floating-point types that can represent the special value "positive infinity"
(public static member constant) [edit]