Re: Copy C'tor - doubt
AY wrote:
I have a situation where I'm required to generate a copy of an object.
I have simplified the class into a tiny one, but in reality its a huge
class with multiple struct types as data member.
Here is my simplified class:
class AB
{
private:
int a;
public:
AB(int ar): a(ar){}
AB(const AB& arg)
{
a = arg.a;
}
};
Better make this:
AB(const AB& arg)
: a(arg.a)
{ }
Also: if you define a copy-ctor you also want to define a copy operator.
(Or as in this case - just go with the copiler generated ones.)
int main()
{
AB* ab = new AB(7);
//AB* cd = new AB;
AB* cd(ab);
return 0;
}
My Qn is in the statement - AB* cd(ab);
Does object 'cd' uses the same memory as object 'ab' ?
Is any memory allocated in the heap for 'cd' like 'ab' [ I do not
think, maybe I'm wrong ] ?
cd and ab are POINTERS to a an object constructed in free-store (heap)
and as such both point to exactly the same AB entitiy. Initializing /
assigning a pointer doesn't invoke anything.
AB* p = ab; // or p(ab); // pointer init: p and ab point to the same thing
AB obj(*ab); // or maybe obj = *ab; // invokation of copy-ctor and
creation of a new object (on the stack)
br,
Martin
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