IsDerivedFrom< Derived, Base > Class Template Reference

Define a constraints base class with a testable value. More...

#include <Workspace/Application/LanguageUtils/classconstraints.h>

Inheritance diagram for IsDerivedFrom< Derived, Base >:

Public Member Functions
	IsDerivedFrom ()

Detailed Description

template<typename Derived, typename Base>
class CSIRO::Application::IsDerivedFrom< Derived, Base >

Taken from "Extensible Templates: Via Inheritance or Traits?", Herb Sutter, C/C++ Users Journal, Feb 2002, pp28-38. This is the "IsDerivedFrom2" class of that article.

To use this class, make it a base class of the template object you want to enforce a condition on. For example:

template<typename T>
class X : IsDerivedFrom<T,Base> {
 // ...
}

This would ensure that T is derived from Base. It would perform the check at compile-time and create no code in the final binary (assuming compiler optimizations are turned on).

Constructor & Destructor Documentation

IsDerivedFrom()

IsDerivedFrom ( )

inline

The default constructor forces a compile-time test on the validity of whatever is in Constraints(). Therefore, to enforce the constraints, make the compiler construct an IsDerivedFrom object. This is most easily done by making it a base class of an object. We try to suppress the unused variable warning if we know how to do it for this compiler.