c++ numeric_limits

std::numeric_limits is a template class in C++ that provides a set of constants and methods for retrieving properties of the numeric types in C++. It is defined in the <limits> header file and allows C++ programs to ask for properties of fundamental data types like int, float, double, etc.

Some of the commonly used properties that can be accessed using std::numeric_limits include:

• The minimum and maximum values of a data type
• The number of digits that can be represented by a data type
• Whether a data type is signed or unsigned
• Whether a data type supports special values like NaN and infinity
• The accuracy of floating-point calculations

Here's an example that demonstrates the use of std::numeric_limits to retrieve properties of the int data type:

#include <iostream>
#include <limits>

int main() {
    std::cout << "Minimum value of int: " << std::numeric_limits<int>::min() << std::endl;
    std::cout << "Maximum value of int: " << std::numeric_limits<int>::max() << std::endl;
    std::cout << "Number of decimal digits of int: " << std::numeric_limits<int>::digits10 << std::endl;
    std::cout << "Is int signed? " << std::numeric_limits<int>::is_signed << std::endl;
    return 0;
}

Output:

Minimum value of int: -2147483648
Maximum value of int: 2147483647
Number of decimal digits of int: 9
Is int signed? 1

In this example, we use std::numeric_limits<int>::min() and std::numeric_limits<int>::max() to retrieve the minimum and maximum values of int. We also use std::numeric_limits<int>::digits10 to retrieve the number of decimal digits that can be represented by int, and std::numeric_limits<int>::is_signed to check whether int is a signed data type