Chris@16: 
Chris@16: //  (C) Copyright Edward Diener 2011,2012
Chris@16: //  Use, modification and distribution are subject to the Boost Software License,
Chris@16: //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt).
Chris@16: 
Chris@16: /*
Chris@16: 
Chris@16:   The succeeding comments in this file are in doxygen format.
Chris@16: 
Chris@16: */
Chris@16: 
Chris@16: /** \file
Chris@16: */
Chris@16: 
Chris@16: #if !defined(BOOST_TTI_HAS_TEMPLATE_HPP)
Chris@16: #define BOOST_TTI_HAS_TEMPLATE_HPP
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/tti/gen/has_template_gen.hpp>
Chris@16: #include <boost/preprocessor/config/config.hpp>
Chris@16: #include <boost/preprocessor/control/iif.hpp>
Chris@16: 
Chris@16: #if BOOST_PP_VARIADICS
Chris@16: 
Chris@16: #include <boost/preprocessor/comparison/equal.hpp>
Chris@16: #include <boost/preprocessor/variadic/elem.hpp>
Chris@16: #include <boost/preprocessor/variadic/size.hpp>
Chris@16: #include <boost/tti/detail/dvm_template_params.hpp>
Chris@16: 
Chris@16: /// Expands to a metafunction which tests whether an inner class template with a particular name exists.
Chris@16: /**
Chris@16: 
Chris@16:     trait = the name of the metafunction.
Chris@16:     ...   = variadic parameters.
Chris@16:     
Chris@16:             The first variadic parameter is the inner class template name.
Chris@16:             
Chris@16:             Following variadic parameters are optional.
Chris@16:             
Chris@16:             If no following variadic parameters exist, then the inner class template 
Chris@16:             being introspected must be all template type parameters ( template parameters 
Chris@16:             starting with `class` or `typename` ) and any number of template type parameters
Chris@16:             can occur.
Chris@16:             
Chris@16:             If the second variadic parameter is BOOST_PP_NIL and no other variadic 
Chris@16:             parameter is given, then just as in the previous case the inner class template 
Chris@16:             being introspected must be all template type parameters ( template parameters 
Chris@16:             starting with `class` or `typename` ) and any number of template type parameters
Chris@16:             can occur. This form is allowed in order to be consistent with using the 
Chris@16:             non-variadic form of this macro.
Chris@16:             
Chris@16:             If the second variadic parameter is a Boost preprocessor library array and no other 
Chris@16:             variadic parameter is given, then the inner class template must have its template 
Chris@16:             parameters matching the sequence in the tuple portion of the Boost PP array. This 
Chris@16:             form is allowed in order to be consistent with using the non-variadic form of this 
Chris@16:             macro.
Chris@16:             
Chris@16:             Otherwise the inner class template must have its template parameters matching the 
Chris@16:             sequence of the optional variadic parameters.
Chris@16:     
Chris@16:     generates a metafunction called "trait" where 'trait' is the first macro parameter.
Chris@16:     
Chris@16:               template<class BOOST_TTI_TP_T>
Chris@16:               struct trait
Chris@16:                 {
Chris@16:                 static const value = unspecified;
Chris@16:                 typedef mpl::bool_<true-or-false> type;
Chris@16:                 };
Chris@16: 
Chris@16:               The metafunction types and return:
Chris@16:     
Chris@16:                 BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
Chris@16:                 
Chris@16:                 returns = 'value' is true if the 'name' template exists within the enclosing type,
Chris@16:                           otherwise 'value' is false.
Chris@16:                           
Chris@16:     Examples:
Chris@16:     
Chris@16:     1) Search for an inner class template called 'MyTemplate', with all template type parameters,
Chris@16:        nested within the class 'MyClass' using a metafunction name of 'MyMeta'.
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate)
Chris@16:     
Chris@16:        or
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,BOOST_PP_NIL) // Non-variadic macro form
Chris@16:     
Chris@16:        MyMeta<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16:     2) Search for an inner class template called 'MyTemplate', with template parameters 
Chris@16:        of 'class T,int x,template<class> class U', nested within the class 'MyClass' 
Chris@16:        using a metafunction name of 'MyMeta'.
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,class,int,template<class> class)
Chris@16:     
Chris@16:        or
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,(3,(class,int,template<class> class))) // Non-variadic macro form
Chris@16:     
Chris@16:        MyMeta<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16: */
Chris@16: #define BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,...) \
Chris@16:   BOOST_PP_IIF \
Chris@16:     ( \
Chris@16:     BOOST_PP_EQUAL \
Chris@16:       ( \
Chris@16:       BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), \
Chris@16:       1 \
Chris@16:       ), \
Chris@16:     BOOST_TTI_DETAIL_VM_TRAIT_HAS_TEMPLATE, \
Chris@16:     BOOST_TTI_DETAIL_VM_CHECK_MORE_THAN_TWO \
Chris@16:     ) \
Chris@16:     (trait,__VA_ARGS__) \
Chris@16: /**/
Chris@16: 
Chris@16: /// Expands to a metafunction which tests whether an inner class template with a particular name exists.
Chris@16: /**
Chris@16: 
Chris@16:     ...   = variadic parameters.
Chris@16:     
Chris@16:             The first variadic parameter is the inner class template name.
Chris@16:             
Chris@16:             Following variadic parameters are optional.
Chris@16:             
Chris@16:             If no following variadic parameters exist, then the inner class template 
Chris@16:             being introspected must be all template type parameters ( template parameters 
Chris@16:             starting with `class` or `typename` ) and any number of template type parameters
Chris@16:             can occur.
Chris@16:             
Chris@16:             If the second variadic parameter is BOOST_PP_NIL and no other variadic 
Chris@16:             parameter is given, then just as in the previous case the inner class template 
Chris@16:             being introspected must be all template type parameters ( template parameters 
Chris@16:             starting with `class` or `typename` ) and any number of template type parameters
Chris@16:             can occur. This form is allowed in order to be consistent with using the 
Chris@16:             non-variadic form of this macro.
Chris@16:             
Chris@16:             If the second variadic parameter is a Boost preprocessor library array and no other 
Chris@16:             variadic parameter is given, then the inner class template must have its template 
Chris@16:             parameters matching the sequence in the tuple portion of the Boost PP array. This 
Chris@16:             form is allowed in order to be consistent with using the non-variadic form of this 
Chris@16:             macro.
Chris@16:             
Chris@16:             Otherwise the inner class template must have its template parameters matching the 
Chris@16:             sequence of the optional variadic parameters.
Chris@16:     
Chris@16:     generates a metafunction called "has_template_'name'" where 'name' is the first variadic parameter.
Chris@16:     
Chris@16:               template<class BOOST_TTI_TP_T>
Chris@16:               struct has_template_'name'
Chris@16:                 {
Chris@16:                 static const value = unspecified;
Chris@16:                 typedef mpl::bool_<true-or-false> type;
Chris@16:                 };
Chris@16: 
Chris@16:               The metafunction types and return:
Chris@16:     
Chris@16:                 BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
Chris@16:                 
Chris@16:                 returns = 'value' is true if the 'name' template exists within the enclosing type,
Chris@16:                           otherwise 'value' is false.
Chris@16:                           
Chris@16:     Examples:
Chris@16:     
Chris@16:     1) Search for an inner class template called 'MyTemplate', with all template type parameters,
Chris@16:        nested within the class 'MyClass'.
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate)
Chris@16:     
Chris@16:        or
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate,BOOST_PP_NIL) // Non-variadic macro form
Chris@16:     
Chris@16:        has_template_MyTemplate<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16:     2) Search for an inner class template called 'MyTemplate' with template parameters 
Chris@16:        of 'class T,int x,template<class> class U' nested within the class 'MyClass'.
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate,class,int,template<class> class)
Chris@16:     
Chris@16:        or
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate,(3,(class,int,template<class> class))) // Non-variadic macro form
Chris@16:     
Chris@16:        has_template_MyTemplate<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16: */
Chris@16: #define BOOST_TTI_HAS_TEMPLATE(...) \
Chris@16:   BOOST_TTI_TRAIT_HAS_TEMPLATE \
Chris@16:     ( \
Chris@16:     BOOST_TTI_HAS_TEMPLATE_GEN \
Chris@16:       ( \
Chris@16:       BOOST_PP_VARIADIC_ELEM(0,__VA_ARGS__) \
Chris@16:       ), \
Chris@16:     __VA_ARGS__ \
Chris@16:     ) \
Chris@16: /**/
Chris@16: 
Chris@16: #else // !BOOST_PP_VARIADICS
Chris@16: 
Chris@16: #include <boost/preprocessor/detail/is_binary.hpp>
Chris@16: #include <boost/tti/detail/dtemplate.hpp>
Chris@16: #include <boost/tti/detail/dtemplate_params.hpp>
Chris@16: 
Chris@16: /// Expands to a metafunction which tests whether an inner class template with a particular name exists.
Chris@16: /**
Chris@16: 
Chris@16:     trait  = the name of the metafunction.
Chris@16:     name   = the inner class template name.
Chris@16:     params = If the  parameter is BOOST_PP_NIL the inner class template 
Chris@16:              being introspected must be all template type parameters ( template parameters 
Chris@16:              starting with `class` or `typename` ) and any number of template type parameters
Chris@16:              can occur.
Chris@16:             
Chris@16:              If the parameter is a Boost preprocessor library array, then the inner class 
Chris@16:              template must have its template parameters matching the sequence in the tuple portion 
Chris@16:              of the Boost PP array.
Chris@16:             
Chris@16:              Otherwise a compiler error occurs.
Chris@16:     
Chris@16:     generates a metafunction called "trait" where 'trait' is the first macro parameter.
Chris@16:     
Chris@16:               template<class BOOST_TTI_TP_T>
Chris@16:               struct trait
Chris@16:                 {
Chris@16:                 static const value = unspecified;
Chris@16:                 typedef mpl::bool_<true-or-false> type;
Chris@16:                 };
Chris@16: 
Chris@16:               The metafunction types and return:
Chris@16:     
Chris@16:                 BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
Chris@16:                 
Chris@16:                 returns = 'value' is true if the 'name' template exists within the enclosing type,
Chris@16:                           otherwise 'value' is false.
Chris@16:                           
Chris@16:     Examples:
Chris@16:     
Chris@16:     1) Search for an inner class template called 'MyTemplate', with all template type parameters,
Chris@16:        nested within the class 'MyClass' using a metafunction name of 'MyMeta'.
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,BOOST_PP_NIL)
Chris@16:     
Chris@16:        MyMeta<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16:     2) Search for an inner class template called 'MyTemplate', with template parameters 
Chris@16:        of 'class T,int x,template<class> class U', nested within the class 'MyClass' 
Chris@16:        using a metafunction name of 'MyMeta'.
Chris@16:     
Chris@16:        BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,(3,(class,int,template<class> class)))
Chris@16:     
Chris@16:        MyMeta<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16: */
Chris@16: #define BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,name,params) \
Chris@16:   BOOST_PP_IIF \
Chris@16:     ( \
Chris@16:     BOOST_PP_IS_BINARY(params), \
Chris@16:     BOOST_TTI_DETAIL_TRAIT_HAS_TEMPLATE_CHECK_PARAMS, \
Chris@16:     BOOST_TTI_DETAIL_TRAIT_CHECK_IS_NIL \
Chris@16:     ) \
Chris@16:     (trait,name,params) \
Chris@16: /**/
Chris@16:   
Chris@16: /// Expands to a metafunction which tests whether an inner class template with a particular name exists.
Chris@16: /**
Chris@16: 
Chris@16:     name   = the inner class template name.
Chris@16:     params = If the  parameter is BOOST_PP_NIL the inner class template 
Chris@16:              being introspected must be all template type parameters ( template parameters 
Chris@16:              starting with `class` or `typename` ) and any number of template type parameters
Chris@16:              can occur.
Chris@16:             
Chris@16:              If the parameter is a Boost preprocessor library array, then the inner class 
Chris@16:              template must have its template parameters matching the sequence in the tuple portion 
Chris@16:              of the Boost PP array.
Chris@16:             
Chris@16:              Otherwise a compiler error occurs.
Chris@16:     
Chris@16:     generates a metafunction called "has_template_'name'" where 'name' is the first macro parameter.
Chris@16:     
Chris@16:               template<class BOOST_TTI_TP_T>
Chris@16:               struct trait
Chris@16:                 {
Chris@16:                 static const value = unspecified;
Chris@16:                 typedef mpl::bool_<true-or-false> type;
Chris@16:                 };
Chris@16: 
Chris@16:               The metafunction types and return:
Chris@16:     
Chris@16:                 BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
Chris@16:                 
Chris@16:                 returns = 'value' is true if the 'name' template exists within the enclosing type,
Chris@16:                           otherwise 'value' is false.
Chris@16:                           
Chris@16:     Examples:
Chris@16:     
Chris@16:     1) Search for an inner class template called 'MyTemplate', with all template type parameters,
Chris@16:        nested within the class 'MyClass'.
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate,BOOST_PP_NIL)
Chris@16:     
Chris@16:        has_template_MyTemplate<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:     
Chris@16:     2) Search for an inner class template called 'MyTemplate' with template parameters 
Chris@16:        of 'class T,int x,template<class> class U' nested within the class 'MyClass'.
Chris@16:     
Chris@16:        BOOST_TTI_HAS_TEMPLATE(MyTemplate,(3,(class,int,template<class> class)))
Chris@16:     
Chris@16:        has_template_MyTemplate<MyClass>::value
Chris@16:     
Chris@16:        is a compile time boolean constant which is either 'true' or 'false'
Chris@16:        if the nested template exists.
Chris@16:        
Chris@16: */
Chris@16: #define BOOST_TTI_HAS_TEMPLATE(name,params) \
Chris@16:   BOOST_TTI_TRAIT_HAS_TEMPLATE \
Chris@16:   ( \
Chris@16:   BOOST_TTI_HAS_TEMPLATE_GEN(name), \
Chris@16:   name, \
Chris@16:   params \
Chris@16:   ) \
Chris@16: /**/
Chris@16: 
Chris@16: #endif // BOOST_PP_VARIADICS
Chris@16: #endif // BOOST_TTI_HAS_TEMPLATE_HPP