| 1 | // Boost.TypeErasure library |
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| 2 | // |
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| 3 | // Copyright 2011 Steven Watanabe |
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| 4 | // |
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| 5 | // Distributed under the Boost Software License Version 1.0. (See |
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| 6 | // accompanying file LICENSE_1_0.txt or copy at |
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| 7 | // http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | // |
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| 9 | // $Id$ |
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| 10 | |
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| 11 | #ifndef BOOST_TYPE_ERASURE_CONCEPT_INTERFACE_HPP_INCLUDED |
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| 12 | #define BOOST_TYPE_ERASURE_CONCEPT_INTERFACE_HPP_INCLUDED |
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| 13 | |
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| 14 | namespace boost { |
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| 15 | namespace type_erasure { |
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| 16 | |
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| 17 | /** |
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| 18 | * The @ref concept_interface class can be specialized to |
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| 19 | * add behavior to an @ref any. An @ref any inherits from |
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| 20 | * all the relevant specializations of @ref concept_interface. |
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| 21 | * |
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| 22 | * @ref concept_interface can be specialized for either |
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| 23 | * primitive or composite concepts. If a concept @c C1 |
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| 24 | * contains another concept @c C2, then the library guarantees |
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| 25 | * that the specialization of @ref concept_interface for |
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| 26 | * @c C2 is a base class of the specialization for @c C1. |
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| 27 | * This means that @c C1 can safely override members of @c C2. |
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| 28 | * |
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| 29 | * @ref concept_interface may only be specialized for user-defined |
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| 30 | * concepts. The library owns the specializations of its own |
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| 31 | * built in concepts. |
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| 32 | * |
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| 33 | * \tparam Concept The concept that we're specializing |
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| 34 | * @ref concept_interface for. One of its |
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| 35 | * placeholders should be @c ID. |
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| 36 | * \tparam Base The base of this class. Specializations of @ref |
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| 37 | * concept_interface must inherit publicly from this type. |
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| 38 | * \tparam ID The placeholder representing this type. |
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| 39 | * \tparam Enable A dummy parameter that can be used for SFINAE. |
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| 40 | * |
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| 41 | * The metafunctions @ref derived, @ref rebind_any, and @ref as_param |
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| 42 | * (which can be applied to @c Base) are useful for determining the |
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| 43 | * argument and return types of functions defined in @ref concept_interface. |
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| 44 | * |
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| 45 | * For dispatching the function use \call. |
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| 46 | */ |
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| 47 | template<class Concept, class Base, class ID, class Enable = void> |
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| 48 | struct concept_interface : Base {}; |
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| 49 | |
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| 50 | } |
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| 51 | } |
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| 52 | |
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| 53 | #endif |
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| 54 | |
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