What is the difference between enable_if and static_assert in C++?

What is the difference between enable_if and static_assert in C++?

Both enable_if and static_assert are used for compile-time checks in C++, but they serve different purposes. enable_if is used to conditionally enable or disable function templates based on type traits, while static_assert is used to assert conditions at compile time and generate a compilation error if the condition is false.

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

Sure! Here's a simple example:

#include <type_traits>

template<typename T, typename = typename std::enable_if<std::is_integral<T>::value>::type>
void process(T value) {
    // Function implementation for integral types
}

This function will only be enabled for integral types.

And what about static_assert?

static_assert is used like this:

static_assert(sizeof(int) == 4, "Integers must be 4 bytes!");

This will cause a compilation error if the size of int is not 4 bytes.

When should I use one over the other?

Use enable_if when you want to enable or disable functions based on type traits, and use static_assert for conditions that must always hold true at compile time, regardless of the type.