Poly< T, Base > Struct Template Reference
#include <polyBase.h>
Inheritance diagram for Poly< T, Base >:
Collaboration diagram for Poly< T, Base >:
Public Member Functions | |
| Poly * | clone () const |
| clone has to return a Poly* to satisfy covariance | |
Detailed Description
template<class T, class Base>
struct classdesc::Poly< T, Base >
struct classdesc::Poly< T, Base >
utility class for building the derived types in a polymorphic heirarchy. Base is the base of the heirarchy.
A possible use is as follows:
class MyBase: public PolyBase<int>
{
static MyBase* create(int); // factory method
};
template <int t>
class MyClass: public Poly<MyClass, MyBase>
{
public:
int type() const {return t;}
};
see also Factory class for another way of doing this static MyBase* MyBase::create(int t) { switch (t) { case 0: return new MyClass<0>; case 1: return new MyClass<1>; case 2: return new MyClass<2>; default: throw std::runtime_error("unknown class construction requested"); } }
See also descriptor specific poly classes, such as polypack.h
The documentation for this struct was generated from the following file:
