What are the differences between constexpr and template functions in C++?

What are the differences between constexpr and template functions in C++?

Both constexpr and template functions are used in C++, but they serve different purposes. constexpr functions are evaluated at compile time, while template functions allow for type flexibility and can be instantiated with different types.

Can you give me an example of each?

Sure! A constexpr function might look like this:

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

And a template function example would be:

template <typename T>
T add(T a, T b) {
    return a + b;
}

When should I use one over the other?

Use constexpr when you need compile-time evaluation for performance or constant expressions. Use template functions when you want to write generic code that works with different data types.

Are there any limitations to using constexpr?

Yes, constexpr functions have some limitations, such as not being able to contain certain statements like loops or dynamic memory allocation in C++11. However, C++14 and later versions have relaxed some of these restrictions.