boost/spirit/home/classic/meta/impl/parser_traits.ipp
/*=============================================================================
Copyright (c) 2002-2003 Joel de Guzman
Copyright (c) 2002-2003 Hartmut Kaiser
Copyright (c) 2003 Martin Wille
http://spirit.sourceforge.net/
Use, modification and distribution is 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_SPIRIT_PARSER_TRAITS_IPP)
#define BOOST_SPIRIT_PARSER_TRAITS_IPP
#include <boost/spirit/home/classic/core/composite/operators.hpp>
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
namespace impl
{
#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
///////////////////////////////////////////////////////////////////////////
//
// from spirit 1.1 (copyright (c) 2001 Bruce Florman)
// various workarounds to support compile time decisions without partial
// template specialization whether a given type is an instance of a
// concrete parser type.
//
///////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////
template <typename T>
struct parser_type_traits
{
// Determine at compile time (without partial specialization)
// whether a given type is an instance of the alternative<A,B>
static T t();
typedef struct { char dummy[1]; } size1_t;
typedef struct { char dummy[2]; } size2_t;
typedef struct { char dummy[3]; } size3_t;
typedef struct { char dummy[4]; } size4_t;
typedef struct { char dummy[5]; } size5_t;
typedef struct { char dummy[6]; } size6_t;
typedef struct { char dummy[7]; } size7_t;
typedef struct { char dummy[8]; } size8_t;
typedef struct { char dummy[9]; } size9_t;
typedef struct { char dummy[10]; } size10_t;
// the following functions need no implementation
template <typename A, typename B>
static size1_t test_(alternative<A, B> const&);
template <typename A, typename B>
static size2_t test_(sequence<A, B> const&);
template <typename A, typename B>
static size3_t test_(sequential_or<A, B> const&);
template <typename A, typename B>
static size4_t test_(intersection<A, B> const&);
template <typename A, typename B>
static size5_t test_(difference<A, B> const&);
template <typename A, typename B>
static size6_t test_(exclusive_or<A, B> const&);
template <typename S>
static size7_t test_(optional<S> const&);
template <typename S>
static size8_t test_(kleene_star<S> const&);
template <typename S>
static size9_t test_(positive<S> const&);
static size10_t test_(...);
BOOST_STATIC_CONSTANT(bool,
is_alternative = (sizeof(size1_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_sequence = (sizeof(size2_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_sequential_or = (sizeof(size3_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_intersection = (sizeof(size4_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_difference = (sizeof(size5_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_exclusive_or = (sizeof(size6_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_optional = (sizeof(size7_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_kleene_star = (sizeof(size8_t) == sizeof(test_(t()))) );
BOOST_STATIC_CONSTANT(bool,
is_positive = (sizeof(size9_t) == sizeof(test_(t()))) );
};
#else
///////////////////////////////////////////////////////////////////////////
struct parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_alternative = false);
BOOST_STATIC_CONSTANT(bool, is_sequence = false);
BOOST_STATIC_CONSTANT(bool, is_sequential_or = false);
BOOST_STATIC_CONSTANT(bool, is_intersection = false);
BOOST_STATIC_CONSTANT(bool, is_difference = false);
BOOST_STATIC_CONSTANT(bool, is_exclusive_or = false);
BOOST_STATIC_CONSTANT(bool, is_optional = false);
BOOST_STATIC_CONSTANT(bool, is_kleene_star = false);
BOOST_STATIC_CONSTANT(bool, is_positive = false);
};
template <typename ParserT>
struct parser_type_traits : public parser_type_traits_base {
// no definition here, fallback for all not explicitly mentioned parser
// types
};
template <typename A, typename B>
struct parser_type_traits<alternative<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_alternative = true);
};
template <typename A, typename B>
struct parser_type_traits<sequence<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_sequence = true);
};
template <typename A, typename B>
struct parser_type_traits<sequential_or<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_sequential_or = true);
};
template <typename A, typename B>
struct parser_type_traits<intersection<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_intersection = true);
};
template <typename A, typename B>
struct parser_type_traits<difference<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_difference = true);
};
template <typename A, typename B>
struct parser_type_traits<exclusive_or<A, B> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_exclusive_or = true);
};
template <typename S>
struct parser_type_traits<optional<S> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_optional = true);
};
template <typename S>
struct parser_type_traits<kleene_star<S> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_kleene_star = true);
};
template <typename S>
struct parser_type_traits<positive<S> >
: public parser_type_traits_base {
BOOST_STATIC_CONSTANT(bool, is_positive = true);
};
#endif // defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
} // namespace impl
///////////////////////////////////////////////////////////////////////////////
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}} // namespace boost::spirit
#endif // !defined(BOOST_SPIRIT_PARSER_TRAITS_IPP)