C++ std::numeric_limits: A Comprehensive Guide

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