I’m getting a segmentation fault which I believe is caused by the copy constructor. However, I can’t find an example like this one anywhere online. I’ve read about shallow copy and deep copy but I’m not sure which category this copy would fall under. Anyone know?
MyObject::MyObject{
lots of things including const and structs, but no pointers
}
MyObject::MyObject( const MyObject& oCopy){
*this = oCopy;//is this deep or shallow?
}
const MyObject& MyObject::operator=(const MyObject& oRhs){
if( this != oRhs ){
members = oRhs.members;
.....//there is a lot of members
}
return *this;
}
MyObject::~MyObject(){
//there is nothing here
}
Code:
const MyObject * mpoOriginal;//this gets initialized in the constructor
int Main(){
mpoOriginal = new MyObject();
return DoSomething();
}
bool DoSomething(){
MyObject *poCopied = new MyObject(*mpoOriginal);//the copy
//lots of stuff going on
delete poCopied;//this causes the crash - can't step into using GDB
return true;
}
EDIT: Added operator= and constructor
SOLVED: Barking up the wrong tree, it ended up being a function calling delete twice on the same object
Wow….
It is neither. It is a call to the assignment operator.
Since you have not finished the construction of the object this is probably ill-advised (though perfectly valid). It is more traditional to define the assignment operator in terms of the copy constructor though (see copy and swap idium).
Basically fine, though normally the result of assignment is not cont.
But if you do it this way you need to divide up your processing a bit to make it exception safe. It should look more like this:
Of course there is a simpler way of doing this using copy and swap idum:
If there is nothing to do in the destructor don’t declare it (unless it needs to be virtual).
Here you are declaring a pointer (not an object) so the constructor is not called (as pointers don;t have constructors).
Here you are calling new to create the object.
Are you sure you want to do this? A dynamically allocated object must be destroyed; ostensibly via delete, but more usually in C++ you wrap pointers inside a smart pointer to make sure the owner correctly and automatically destroys the object.
But since you probably don’t want a dynamic object. What you want is automatic object that is destroyed when it goes out of scope. Also you probably should not be using a global variable (pass it as a parameter otherwise your code is working using the side affects that are associated with global state).
You do not need to call new to make a copy just create an object (passing the object you want to copy).