must_have_base Struct Template Reference
[Constraints Utility Library]

#include <stlsoft/util/constraints.hpp>

List of all members.

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Detailed Description

template<typename D, typename B>
struct stlsoft::must_have_base< D, B >

Constraint to ensure that the one type is convertible to another via inheritance.

Parameters:

	D	The derived type
	B	The base type

It may be used as follows:

  class Parent {};
  class Child : public Parent {};
  class Orphan {};

  stlsoft::must_have_base<Parent, Parent>();  // Ok
  stlsoft::must_have_base<Child, Parent>();   // Ok
  stlsoft::must_have_base<Child, Child>();    // Ok
  stlsoft::must_have_base<Child, Parent>();   // Compile error!

  stlsoft::must_have_base<Orphan, Parent>();  // Compile error!
  stlsoft::must_have_base<Orphan, Child>();   // Compile error!
  stlsoft::must_have_base<Parent, Orphan>();  // Compile error!
  stlsoft::must_have_base<Child, Orphan>();   // Compile error!

Note:

This is borrowed from Bjarne Stroustrup's idea as posted to comp.lang.c++.moderated 17th February 2001.

See also:

stlsoft::must_be_derived

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The documentation for this struct was generated from the following file:

• stlsoft/util/constraints.hpp