Implement abstract class as a local class? pros and cons
for some reason I'm thinking on implementing interface within a some function(method) as local class.
Consider following:
class A{
public:
virtual void MethodToOverride() = 0;
};
A * GetPtrToAImplementation(){
class B : public A {
public:
B(){}
~B(){}
void MethodToOverride() {
//do something
}
};
return static_cast<A *>(new B());
}
int _tmain(int argc, _TCHAR* argv[])
{
A * aInst = GetPtrToAImplementation();
aInst->MethodToOverride();
delete aInst;
return 0;
}
the reasons why I'm doing this are:
- I'm lazy to implement class (B) in separate fi开发者_如何学Goles
- MethodToOverride just delegates call to other class
- Class B shouldn't be visible to other users
- no need to worry about deleting aInst since smart pointers are used in real implementation
So my question is if I'm doing this right?
Thanks in advance!
You could define
B
in the unnamed namespace of the implementation file where you implementGetPtrToAImplementation()
.A
should have a virtual dtor.By the current C++ standard, you cannot use local classes as template arguments. (Which means you can't use them with the STL, for example.)
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