C++ is there a difference between assignment inside a pass by value and pass by reference function?
- by Rémy DAVID
Is there a difference between foo and bar:
class A
{
Object __o;
void foo(Object& o)
{
__o = o;
}
void bar(Object o)
{
__o = o;
}
}
As I understand it, foo performs no copy operation on object o when it is called, and one copy operation for assignment. Bar performs one copy operation on object o when it is called and another one for assignment. So I can more or less say that foo uses 2 times less memory than bar (if o is big enough). Is that correct ?
Is it possible that the compiler optimises the bar function to perform only one copy operation on o ? i.e. makes __o pointing on the local copy of argument o instead of creating a new copy?
