Using type traits in C++ template functions, is it possible to convert a value to a T of the same type?

Question

I'm trying to write a template function like this

template<typename T>
T doSomething() { 
    //Code

    if (std::is_same<T, int>::value) { 
        return getInt();   // A library function returning an int
    } else if (std::is_same<T, bool>::value) {
        return getBool();  // A library function returning a bool
    } else { 
        throw;
    }
}

that calls different functions depending on the template parameter given and returns a value which, at runtime, is guaranteed to have the same type as T. However, the compiler gives me this error: 'return': cannot convert from 'int' to 'T' I guess I could use something like reinterpret_cast, but this seems to be unsafe and bad practice in this scenario.

So, is there a way to return different types from a template function depending on the template parameter in C++?

Answer 1

So, is there a way to return different types from a template function depending on the template parameter in C++?

Yes, you can use C++17 constexpr if

template<typename T>
T doSomething() { 
    //Code

    if constexpr (std::is_same<T, int>::value) { 
        return getInt();   // A library function returning an int
    } else if constexpr (std::is_same<T, bool>::value) {
        return getBool();  // A library function returning a bool
    } else { 
        throw;
    }
}