Question

template <class T>
void MyClass<T>::MyMethod()
{
    // ...

    // Which of the following initialization is better?
    T MyVariable1 = 1;                  // 1st
    T MyVariable2 = 2.0;                // 2nd
    T MyVariable3 = static_cast<T>(3);  // 3rd

    // ...
}

Which one is better?

EDIT: T is a primitive type.

Answer 1

If T can only be a primitive type (int, float, etc.), I don’t think there’s any difference; in all cases, the compiler will perform the relevant conversion (and will probably perform the substitution at compile-time).

If T is a user-defined type, then obviously these won’t compile, unless it has the appropriate constructors defined. At which point, it may make a difference (e.g. if you have both T::T(int) and T::T(double) defined).