Suppose the class MyClass has constructor:
MyClass::MyClass( ... ) {
var = new OtherClass( ... );
}
and suppose the class OtherClass has copy constructor:
OtherClass::OtherClass(const OtherClass &obj) {
for (int i = 0; i < array_size; ++i) {
array[i] = obj.array[i];
}
}
Is the below a recommended way to write the copy constructor for MyClass?
MyClass::MyClass(const MyClass &obj) {
var = new OtherClass(*obj.var);
}
I'm asking because I haven't been able to find an example of the dereferencing syntax the above copy constructor uses.
Edit: I'm sorry, I left 开发者_StackOverflow中文版a typo in the copy constructor (introduced while I was trying to make the code example abstract): *obj.array
was intended to be *obj.var
.
No, that doesn't really make sense. What makes sense is this:
MyClass::MyClass(const MyClass &obj) {
var = new OtherClass(*obj.var);
}
Or rather:
MyClass::MyClass(const MyClass &obj)
:var(new OtherClass(*obj.var))
{}
Assuming that var
is actually a member of MyClass and a pointer to OtherClass
, I would write
MyClass::MyClass(const MyClass &obj) : var(new OtherClass(obj.array))
{
...
}
Yes, it's generally recommended that copy ctors take const
reference parameters.
You do not need to dereference a reference. Change your code to:
MyClass::MyClass(const MyClass &obj) {
var = new OtherClass(obj.array);
}
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