projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | /*============================================================================= |
| 2 | Copyright (c) 2001-2011 Joel de Guzman | |
| 3 | ||
| 4 | Distributed under the Boost Software License, Version 1.0. (See accompanying | |
| 5 | file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
| 6 | ==============================================================================*/ | |
| 7 | #if !defined(BOOST_SPIRIT_EXPAND_ARG_FEB_19_2007_1107AM) | |
| 8 | #define BOOST_SPIRIT_EXPAND_ARG_FEB_19_2007_1107AM | |
| 9 | ||
| 10 | #if defined(_MSC_VER) | |
| 11 | #pragma once | |
| 12 | #endif | |
| 13 | ||
| 14 | #include <boost/mpl/bool.hpp> | |
| 15 | #include <boost/mpl/or.hpp> | |
| 16 | #include <boost/mpl/identity.hpp> | |
| 17 | #include <boost/mpl/eval_if.hpp> | |
| 18 | #include <boost/utility/result_of.hpp> | |
| 19 | #include <boost/type_traits/is_scalar.hpp> | |
| 20 | #include <boost/spirit/home/support/string_traits.hpp> | |
| 21 | ||
| 22 | namespace boost { namespace spirit { namespace detail | |
| 23 | { | |
| 24 | /////////////////////////////////////////////////////////////////////////// | |
| 25 | template <typename Context> | |
| 26 | struct expand_arg | |
| 27 | { | |
| 28 | template <typename T> | |
| 29 | struct result_type | |
| 30 | { | |
| 31 | // This is a temporary hack. The better way is to detect if T | |
| 32 | // can be called given unused context. | |
| 33 | typedef typename | |
| 34 | mpl::eval_if< | |
| 35 | mpl::or_<is_scalar<T>, traits::is_string<T> > | |
| 36 | , mpl::identity<T const &> | |
| 37 | , boost::result_of<T(unused_type, Context)> | |
| 38 | >::type | |
| 39 | type; | |
| 40 | }; | |
| 41 | ||
| 42 | template <typename T> | |
| 43 | struct result; | |
| 44 | ||
| 45 | template <typename F, typename A0> | |
| 46 | struct result<F(A0)> | |
| 47 | : result_type<A0> {}; | |
| 48 | ||
| 49 | template <typename F, typename A0> | |
| 50 | struct result<F(A0&)> | |
| 51 | : result_type<A0> {}; | |
| 52 | ||
| 53 | expand_arg(Context& context_) | |
| 54 | : context(context_) | |
| 55 | { | |
| 56 | } | |
| 57 | ||
| 58 | template <typename T> | |
| 59 | typename result_type<T>::type | |
| 60 | call(T const& f, mpl::false_) const | |
| 61 | { | |
| 62 | return f(unused, context); | |
| 63 | } | |
| 64 | ||
| 65 | template <typename T> | |
| 66 | typename result_type<T>::type | |
| 67 | call(T const& val, mpl::true_) const | |
| 68 | { | |
| 69 | return val; | |
| 70 | } | |
| 71 | ||
| 72 | template <typename T> | |
| 73 | typename result_type<T>::type | |
| 74 | operator()(T const& x) const | |
| 75 | { | |
| 76 | return call(x, mpl::or_<is_scalar<T>, traits::is_string<T> >()); | |
| 77 | } | |
| 78 | ||
| 79 | Context& context; | |
| 80 | ||
| 81 | private: | |
| 82 | // silence MSVC warning C4512: assignment operator could not be generated | |
| 83 | expand_arg& operator= (expand_arg const&); | |
| 84 | }; | |
| 85 | ||
| 86 | }}} | |
| 87 | ||
| 88 | #endif |