Right way to conditionally initialize a C++ member variable?

Question

I\'m sure this is a really simple question. The following code shows what I\'m trying to do:

class MemberClass {
public:
    MemberClass(int abc){ }
};

clas         


        

Answer 1

Use the initializer list syntax:

class MyClass {
public:
    MemberClass m_class;
    MyClass(int xyz) : m_class(xyz == 42 ? MemberClass(12) : MemberClass(32)
                               /* see the comments, cleaner as xyz == 42 ? 12 : 32*/)
    { }
};

Probably cleaner with a factory:

MemberClass create_member(int x){
   if(xyz == 42)
     return MemberClass(12);
    // ...
}

//...
 MyClass(int xyz) : m_class(create_member(xyz))