Declare a reference and initialize later?

Question

I have a reference to MyOjbect, but the the exact object depends on a condition. So I want to do something like this:

MyObject& ref; 
if([co         


        

Answer 1

You need to initliaze it. But if you would like to conditionally initialize it, you can do something like this:

MyObject& ref = (condition) ? MyObject([something]) : MyObject([something else]);

Answer 2

AFAIK this can't be done with a reference. You'd have to use a pointer:

MyClass *ptr;

if (condition)
    ptr = &object;
else
    ptr = &other_object;

The pointer will act similar to a reference. Just don't forget to use -> for member access.

Answer 3

I usually do this (C++ 11 or later):

std::shared_ptr<ObjType> pObj;
if(condition)
    pObj = std::make_shared<ObjType>(args_to_constructor_1);
else
    pObj = std::make_shared<ObjType>(args_to_constructor_2);

which is clean and allows using object definition with (possibly different) constructions, a thing you can't do directly with pointers as the compiler will complain from using temporary objects.

Answer 4

In C++, you can't declare a reference without initialization. You must initialize it.