How do I use constexpr (C++11) in C++11?

In C++11, the `constexpr` specifier can be used to declare that it is possible to evaluate the value of a function or variable at compile time. This allows for more optimization opportunities, as values can be computed during compilation rather than at runtime.

Here’s a simple example of how to use `constexpr` in C++11:


        constexpr int square(int x) {
            return x * x;
        }

        int main() {
            constexpr int value = square(5);
            std::cout << value;  // Outputs: 25
            return 0;
        }