Edit: /usr/include/boost/tti/has_template.hpp (14727B)
// (C) Copyright Edward Diener 2011,2012
// Use, modification and distribution are subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt).
#if !defined(BOOST_TTI_HAS_TEMPLATE_HPP)
#define BOOST_TTI_HAS_TEMPLATE_HPP
/*
The succeeding comments in this file are in doxygen format.
*/
/** \file
*/
#include
#include
#include
#if BOOST_PP_VARIADICS
#include
#include
#include
#include
/// A macro which expands to a metafunction which tests whether an inner class template with a particular name exists.
/**
BOOST_TTI_TRAIT_HAS_TEMPLATE is a macro which expands to a metafunction.
The metafunction tests whether an inner class template with a particular name exists.
The macro takes the form of BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,...) where
trait = the name of the metafunction
... = variadic parameters.
The first variadic parameter is the inner class template name.
Following variadic parameters are optional.
If no following variadic parameters exist, then the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur.
If the second variadic parameter is BOOST_PP_NIL and no other variadic
parameter is given, then just as in the previous case the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur. This form is allowed in order to be consistent with using the
non-variadic form of this macro.
If the second variadic parameter is a Boost preprocessor library array and no other
variadic parameter is given, then the inner class template must have its template
parameters matching the sequence in the tuple portion of the Boost PP array. This
form is allowed in order to be consistent with using the non-variadic form of this
macro.
Otherwise the inner class template must have its template parameters matching the
sequence of the optional variadic parameters.
BOOST_TTI_TRAIT_HAS_TEMPLATE generates a metafunction called "trait" where 'trait' is the first macro parameter.
@code
template
struct trait
{
static const value = unspecified;
typedef mpl::bool_ type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
The enclosing type can be a class, struct, or union.
returns = 'value' is true if the 'name' template exists within the enclosing type,
otherwise 'value' is false.
@endcode
Examples:
@code
1) Search for an inner class template called 'MyTemplate', with all template type parameters,
nested within the class 'MyClass' using a metafunction name of 'MyMeta'.
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate)
or
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,BOOST_PP_NIL) // Non-variadic macro form
MyMeta::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
2) Search for an inner class template called 'MyTemplate', with template parameters
of 'class T,int x,template class U', nested within the class 'MyClass'
using a metafunction name of 'MyMeta'.
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,class,int,template class)
or
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,(3,(class,int,template class))) // Non-variadic macro form
MyMeta::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
@endcode
*/
#define BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,...) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL \
( \
BOOST_PP_VARIADIC_SIZE(__VA_ARGS__), \
1 \
), \
BOOST_TTI_DETAIL_VM_TRAIT_HAS_TEMPLATE, \
BOOST_TTI_DETAIL_VM_CHECK_MORE_THAN_TWO \
) \
(trait,__VA_ARGS__) \
/**/
/// A macro which expands to a metafunction which tests whether an inner class template with a particular name exists.
/**
BOOST_TTI_HAS_TEMPLATE is a macro which expands to a metafunction.
The metafunction tests whether an inner class template with a particular name exists.
The macro takes the form of BOOST_TTI_HAS_TEMPLATE(...) where
... = variadic parameters.
The first variadic parameter is the inner class template name.
Following variadic parameters are optional.
If no following variadic parameters exist, then the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur.
If the second variadic parameter is BOOST_PP_NIL and no other variadic
parameter is given, then just as in the previous case the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur. This form is allowed in order to be consistent with using the
non-variadic form of this macro.
If the second variadic parameter is a Boost preprocessor library array and no other
variadic parameter is given, then the inner class template must have its template
parameters matching the sequence in the tuple portion of the Boost PP array. This
form is allowed in order to be consistent with using the non-variadic form of this
macro.
Otherwise the inner class template must have its template parameters matching the
sequence of the optional variadic parameters.
BOOST_TTI_HAS_TEMPLATE generates a metafunction called "has_template_'name'" where 'name' is the first variadic parameter.
@code
template
struct has_template_'name'
{
static const value = unspecified;
typedef mpl::bool_ type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
The enclosing type can be a class, struct, or union.
returns = 'value' is true if the 'name' template exists within the enclosing type,
otherwise 'value' is false.
@endcode
Examples:
@code
1) Search for an inner class template called 'MyTemplate', with all template type parameters,
nested within the class 'MyClass'.
BOOST_TTI_HAS_TEMPLATE(MyTemplate)
or
BOOST_TTI_HAS_TEMPLATE(MyTemplate,BOOST_PP_NIL) // Non-variadic macro form
has_template_MyTemplate::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
2) Search for an inner class template called 'MyTemplate' with template parameters
of 'class T,int x,template class U' nested within the class 'MyClass'.
BOOST_TTI_HAS_TEMPLATE(MyTemplate,class,int,template class)
or
BOOST_TTI_HAS_TEMPLATE(MyTemplate,(3,(class,int,template class))) // Non-variadic macro form
has_template_MyTemplate::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
@endcode
*/
#define BOOST_TTI_HAS_TEMPLATE(...) \
BOOST_TTI_TRAIT_HAS_TEMPLATE \
( \
BOOST_TTI_HAS_TEMPLATE_GEN \
( \
BOOST_PP_VARIADIC_ELEM(0,__VA_ARGS__) \
), \
__VA_ARGS__ \
) \
/**/
#else // !BOOST_PP_VARIADICS
#include
#include
#include
/// A macro which expands to a metafunction which tests whether an inner class template with a particular name exists.
/**
BOOST_TTI_TRAIT_HAS_TEMPLATE is a macro which expands to a metafunction.
The metafunction tests whether an inner class template with a particular name exists.
The macro takes the form of BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,name,params) where
trait = the name of the metafunction
name = the inner class template name
params = If the parameter is BOOST_PP_NIL the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur.
If the parameter is a Boost preprocessor library array, then the inner class
template must have its template parameters matching the sequence in the tuple portion
of the Boost PP array.
If the parameter is anything else a compiler error occurs.
BOOST_TTI_TRAIT_HAS_TEMPLATE generates a metafunction called "trait" where 'trait' is the first macro parameter.
@code
template
struct trait
{
static const value = unspecified;
typedef mpl::bool_ type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
The enclosing type can be a class, struct, or union.
returns = 'value' is true if the 'name' template exists within the enclosing type,
otherwise 'value' is false.
@endcode
Examples:
@code
1) Search for an inner class template called 'MyTemplate', with all template type parameters,
nested within the class 'MyClass' using a metafunction name of 'MyMeta'.
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,BOOST_PP_NIL)
MyMeta::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
2) Search for an inner class template called 'MyTemplate', with template parameters
of 'class T,int x,template class U', nested within the class 'MyClass'
using a metafunction name of 'MyMeta'.
BOOST_TTI_TRAIT_HAS_TEMPLATE(MyMeta,MyTemplate,(3,(class,int,template class)))
MyMeta::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
@endcode
*/
#define BOOST_TTI_TRAIT_HAS_TEMPLATE(trait,name,params) \
BOOST_PP_IIF \
( \
BOOST_PP_IS_BINARY(params), \
BOOST_TTI_DETAIL_TRAIT_HAS_TEMPLATE_CHECK_PARAMS, \
BOOST_TTI_DETAIL_TRAIT_CHECK_IS_NIL \
) \
(trait,name,params) \
/**/
/// A macro which expands to a metafunction which tests whether an inner class template with a particular name exists.
/**
BOOST_TTI_HAS_TEMPLATE is a macro which expands to a metafunction.
The metafunction tests whether an inner class template with a particular name exists.
The macro takes the form of BOOST_TTI_HAS_TEMPLATE(name,params) where
name = the inner class template name
params = If the parameter is BOOST_PP_NIL the inner class template
being introspected must be all template type parameters ( template parameters
starting with `class` or `typename` ) and any number of template type parameters
can occur.
If the parameter is a Boost preprocessor library array, then the inner class
template must have its template parameters matching the sequence in the tuple portion
of the Boost PP array.
If the parameter is anything else a compiler error occurs.
BOOST_TTI_HAS_TEMPLATE generates a metafunction called "has_template_'name'" where 'name' is the first macro parameter.
@code
template
struct has_template_'name'
{
static const value = unspecified;
typedef mpl::bool_ type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'.
The enclosing type can be a class, struct, or union.
returns = 'value' is true if the 'name' template exists within the enclosing type,
otherwise 'value' is false.
@endcode
Examples:
@code
1) Search for an inner class template called 'MyTemplate', with all template type parameters,
nested within the class 'MyClass'.
BOOST_TTI_HAS_TEMPLATE(MyTemplate,BOOST_PP_NIL)
has_template_MyTemplate::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
2) Search for an inner class template called 'MyTemplate' with template parameters
of 'class T,int x,template class U' nested within the class 'MyClass'.
BOOST_TTI_HAS_TEMPLATE(MyTemplate,(3,(class,int,template class)))
has_template_MyTemplate::value
is a compile time boolean constant which is either 'true' or 'false'
if the nested template exists.
@endcode
*/
#define BOOST_TTI_HAS_TEMPLATE(name,params) \
BOOST_TTI_TRAIT_HAS_TEMPLATE \
( \
BOOST_TTI_HAS_TEMPLATE_GEN(name), \
name, \
params \
) \
/**/
#endif // BOOST_PP_VARIADICS
#endif // BOOST_TTI_HAS_TEMPLATE_HPP