How do I use type traits to branch at compile time in C++?

In C++, type traits are a powerful tool that allows you to make compile-time decisions based on the properties of types. By utilizing these traits, you can conditionally enable or disable certain code paths, which can lead to more efficient and safer code.

Type traits are part of the `` header and provide a variety of functionalities. Here’s how you can use them to branch at compile time:

#include <iostream>
#include <type_traits>

template<typename T>
void printTypeInfo() {
    if constexpr (std::is_integral<T>::value) {
        std::cout << "T is an integral type." << std::endl;
    } else {
        std::cout << "T is not an integral type." << std::endl;
    }
}

int main() {
    printTypeInfo<int>();         // Output: T is an integral type.
    printTypeInfo<double>();      // Output: T is not an integral type.
    return 0;
}
    

In this example, we define a function template `printTypeInfo` that checks if the type `T` is an integral type using `std::is_integral`. The `if constexpr` statement allows us to evaluate the condition at compile time. Depending on the result, different code paths are executed.