What is the difference between constexpr and const in C++11?

What is the difference between constexpr and const in C++11?

In C++11, const defines a constant variable whose value cannot be changed, while constexpr indicates that a variable or function can be evaluated at compile time.

Can you give me an example of how to use constexpr?

Sure! Here's a simple example:

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

constexpr int result = square(5);

Are there any limitations to using constexpr?

Yes, constexpr functions must have a return type and contain only a single return statement or be defined in a way that allows for compile-time evaluation.

When should I use const instead of constexpr?

Use const when you need a constant value that can be initialized at runtime, while constexpr is preferred for values known at compile time.