Преимущества списков Инициализации

Я думаю, что единственный способ инициализировать константные элементы данных - это список инициализации

Например. в заголовке:

class C
{
    C();
private:
    const int x;
    int y;
}

И в файле cpp:

C::C() :
    x( 10 ),
    y( 10 )
{
    x = 20; // fails
    y = 20;
}

Remember that there is a distinct difference between a copy constructor and an assignment operator:

• the copy ctor constructs a new object using some other instance as a place to get initialization information from.
• the assignment operator modifies an already existing object that has already been fully constructed (even if it's only by using a default constructor)

So in your second example, some work has already been done to create name by the time that

 name=n;

is reached.

However, it's quite possible (especially in this simple example) that the work done is vanishingly small (probably just zeroing out some data members in the string object) and that the work is optimized away altogether in an optimized build. but it's still considered good form to use initializer lists whenever possible.

Это отличный способ инициализировать члены, которые:

• являются константными
• не имеют конструктора по умолчанию (он частный)