Mercurial > hg > vamp-build-and-test
diff DEPENDENCIES/generic/include/boost/variant/get.hpp @ 16:2665513ce2d3
Add boost headers
author | Chris Cannam |
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date | Tue, 05 Aug 2014 11:11:38 +0100 |
parents | |
children | c530137014c0 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DEPENDENCIES/generic/include/boost/variant/get.hpp Tue Aug 05 11:11:38 2014 +0100 @@ -0,0 +1,203 @@ +//----------------------------------------------------------------------------- +// boost variant/get.hpp header file +// See http://www.boost.org for updates, documentation, and revision history. +//----------------------------------------------------------------------------- +// +// Copyright (c) 2003 +// Eric Friedman, Itay Maman +// +// Distributed under 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) + +#ifndef BOOST_VARIANT_GET_HPP +#define BOOST_VARIANT_GET_HPP + +#include <exception> + +#include "boost/config.hpp" +#include "boost/detail/workaround.hpp" +#include "boost/throw_exception.hpp" +#include "boost/utility/addressof.hpp" +#include "boost/variant/variant_fwd.hpp" + +#include "boost/type_traits/add_reference.hpp" +#include "boost/type_traits/add_pointer.hpp" + +#if BOOST_WORKAROUND(BOOST_MSVC, < 1300) +# include "boost/mpl/bool.hpp" +# include "boost/mpl/or.hpp" +# include "boost/type_traits/is_same.hpp" +#endif + +namespace boost { + +////////////////////////////////////////////////////////////////////////// +// class bad_get +// +// The exception thrown in the event of a failed get of a value. +// +class bad_get + : public std::exception +{ +public: // std::exception implementation + + virtual const char * what() const BOOST_NOEXCEPT_OR_NOTHROW + { + return "boost::bad_get: " + "failed value get using boost::get"; + } + +}; + +////////////////////////////////////////////////////////////////////////// +// function template get<T> +// +// Retrieves content of given variant object if content is of type T. +// Otherwise: pointer ver. returns 0; reference ver. throws bad_get. +// + +namespace detail { namespace variant { + +// (detail) class template get_visitor +// +// Generic static visitor that: if the value is of the specified type, +// returns a pointer to the value it visits; else a null pointer. +// +template <typename T> +struct get_visitor +{ +private: // private typedefs + + typedef typename add_pointer<T>::type pointer; + typedef typename add_reference<T>::type reference; + +public: // visitor typedefs + + typedef pointer result_type; + +public: // visitor interfaces + +#if !BOOST_WORKAROUND(BOOST_MSVC, < 1300) + + pointer operator()(reference operand) const + { + return boost::addressof(operand); + } + + template <typename U> + pointer operator()(const U&) const + { + return static_cast<pointer>(0); + } + +#else // MSVC6 + +private: // helpers, for visitor interfaces (below) + + pointer execute_impl(reference operand, mpl::true_) const + { + return boost::addressof(operand); + } + + template <typename U> + pointer execute_impl(const U& operand, mpl::false_) const + { + return static_cast<pointer>(0); + } + +public: // visitor interfaces + + template <typename U> + pointer operator()(U& operand) const + { + // MSVC6 finds normal implementation (above) ambiguous, + // so we must explicitly disambiguate + + typedef typename mpl::or_< + is_same<U, T> + , is_same<const U, T> + >::type U_is_T; + + return execute_impl(operand, U_is_T()); + } + +#endif // MSVC6 workaround + +}; + +}} // namespace detail::variant + +#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) +# define BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(t) \ + BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t) +#else +# define BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(t) \ + , t* = 0 +#endif + +template <typename U, BOOST_VARIANT_ENUM_PARAMS(typename T) > +inline + typename add_pointer<U>::type +get( + boost::variant< BOOST_VARIANT_ENUM_PARAMS(T) >* operand + BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(U) + ) +{ + typedef typename add_pointer<U>::type U_ptr; + if (!operand) return static_cast<U_ptr>(0); + + detail::variant::get_visitor<U> v; + return operand->apply_visitor(v); +} + +template <typename U, BOOST_VARIANT_ENUM_PARAMS(typename T) > +inline + typename add_pointer<const U>::type +get( + const boost::variant< BOOST_VARIANT_ENUM_PARAMS(T) >* operand + BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(U) + ) +{ + typedef typename add_pointer<const U>::type U_ptr; + if (!operand) return static_cast<U_ptr>(0); + + detail::variant::get_visitor<const U> v; + return operand->apply_visitor(v); +} + +template <typename U, BOOST_VARIANT_ENUM_PARAMS(typename T) > +inline + typename add_reference<U>::type +get( + boost::variant< BOOST_VARIANT_ENUM_PARAMS(T) >& operand + BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(U) + ) +{ + typedef typename add_pointer<U>::type U_ptr; + U_ptr result = get<U>(&operand); + + if (!result) + boost::throw_exception(bad_get()); + return *result; +} + +template <typename U, BOOST_VARIANT_ENUM_PARAMS(typename T) > +inline + typename add_reference<const U>::type +get( + const boost::variant< BOOST_VARIANT_ENUM_PARAMS(T) >& operand + BOOST_VARIANT_AUX_GET_EXPLICIT_TEMPLATE_TYPE(U) + ) +{ + typedef typename add_pointer<const U>::type U_ptr; + U_ptr result = get<const U>(&operand); + + if (!result) + boost::throw_exception(bad_get()); + return *result; +} + +} // namespace boost + +#endif // BOOST_VARIANT_GET_HPP