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- //==============================================================================
- // Copyright 2003 - 2011 LASMEA UMR 6602 CNRS/Univ. Clermont II
- // Copyright 2009 - 2011 LRI UMR 8623 CNRS/Univ Paris Sud XI
- // Copyright 2011 Eric Niebler
- //
- // Distributed under the Boost Software License, Version 1.0.
- // See accompanying file LICENSE.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt
- //==============================================================================
- #ifndef BOOST_PROTO_PREPROCESSOR_REMOVE_TYPENAME_HPP_INCLUDED
- #define BOOST_PROTO_PREPROCESSOR_REMOVE_TYPENAME_HPP_INCLUDED
- /*!
- * \file
- * \brief Defines the BOOST_PROTO_REMOVE_TYPENAME macro
- */
- #include <boost/preprocessor/cat.hpp>
- #include <boost/preprocessor/expand.hpp>
- #include <boost/preprocessor/tuple/eat.hpp>
- #include <boost/preprocessor/control/iif.hpp>
- #include <boost/preprocessor/detail/is_unary.hpp>
- //==============================================================================
- // Boost.Preprocessor author P. Mensodines confirmed on an Boost email thread
- // (subject ``check if a token is a keyword (was "BOOST_PP_IS_UNARY()")'')
- // that it is OK to used `PP_IS_UNARY()` to check if tokens match predefined
- // "keyword" as it is done by the macros below (even if `PP_IS_UNARY()` is
- // technically only part of Boost.Preprocessor private API).
- //==============================================================================
- //==============================================================================
- // `checking_prefix ## tokens` expand to unary (e.g., `(1)`) iff `tokens` start
- // with keyword to check.
- //==============================================================================
- #define BOOST_PROTO_DETAILS_KEYWORD_FACILITY_IS_FRONT(T, CHECKING_PREFIX) \
- BOOST_PP_IS_UNARY(BOOST_PP_CAT(CHECKING_PREFIX, T)) \
- /**/
- //==============================================================================
- // `is_front_macro(tokens)` is 1 iff `tokens` start with keyword to remove.
- // `removing_prefix ## <keyword-to-remove>` must expand to nothing.
- //==============================================================================
- #define BOOST_PROTO_DETAILS_KEYWORD_FACILITY_REMOVE_FRONT(TOKENS, IS_FRONT_MACRO, REMOVING_PREFIX) \
- BOOST_PP_EXPAND( /* without EXPAND doesn't expand on MSVC */ \
- BOOST_PP_IIF( \
- IS_FRONT_MACRO(TOKENS) \
- , BOOST_PP_CAT \
- , TOKENS BOOST_PP_TUPLE_EAT(2) \
- )(REMOVING_PREFIX, TOKENS) \
- ) \
- /**/
- #define BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_IS_typename (1) /* unary */
- #define typename_BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_IS (1) /* unary */
- #define BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_REMOVE_typename /* nothing */
- #define typename_BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_REMOVE /* nothing */
- #define BOOST_PROTO_DETAILS_KEYWORD_IS_TYPENAME_FRONT(TOKENS) \
- BOOST_PROTO_DETAILS_KEYWORD_FACILITY_IS_FRONT(TOKENS, BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_IS_) \
- /**/
- //==============================================================================
- /*!
- * \ingroup preprocessor
- * For any symbol \c X, this macro returns the same symbol from which a potential
- * leading \c typename keyword has been removed. If no typename keyword is present,
- * this macros evaluates to \c X itself without error.
- *
- * The original implementation of this macro is from Lorenzo Caminiti.
- *
- * \param X Symbol to remove \c typename from
- */
- //==============================================================================
- #define BOOST_PROTO_REMOVE_TYPENAME(X) \
- BOOST_PROTO_DETAILS_KEYWORD_FACILITY_REMOVE_FRONT( \
- X \
- , BOOST_PROTO_DETAILS_KEYWORD_IS_TYPENAME_FRONT \
- , BOOST_PROTO_DETAILS_KEYWORD_TYPENAME_REMOVE_ \
- ) \
- /**/
- #endif
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