Blame view

3rdparty/boost_1_81_0/boost/proto/literal.hpp 3.41 KB
dbf9e800   Hu Chunming   提交_GLIBCXX_USE_CX...
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
  ///////////////////////////////////////////////////////////////////////////////
  /// \file literal.hpp
  /// The literal\<\> terminal wrapper, and the proto::lit() function for
  /// creating literal\<\> wrappers.
  //
  //  Copyright 2008 Eric Niebler. 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_PROTO_LITERAL_HPP_EAN_01_03_2007
  #define BOOST_PROTO_LITERAL_HPP_EAN_01_03_2007
  
  #include <boost/config.hpp>
  #include <boost/proto/proto_fwd.hpp>
  #include <boost/proto/expr.hpp>
  #include <boost/proto/traits.hpp>
  #include <boost/proto/extends.hpp>
  
  namespace boost { namespace proto
  {
      namespace utility
      {
          /// \brief A simple wrapper for a terminal, provided for
          /// ease of use.
          ///
          /// A simple wrapper for a terminal, provided for
          /// ease of use. In all cases, <tt>literal\<X\> l(x);</tt>
          /// is equivalent to <tt>terminal\<X\>::type l = {x};</tt>.
          ///
          /// The \c Domain template parameter defaults to
          /// \c proto::default_domain.
          template<
              typename T
            , typename Domain // = default_domain
          >
          struct literal
            : extends<basic_expr<tag::terminal, term<T>, 0>, literal<T, Domain>, Domain>
          {
          private:
              typedef basic_expr<tag::terminal, term<T>, 0> terminal_type;
              typedef extends<terminal_type, literal<T, Domain>, Domain> base_type;
              typedef literal<T, Domain> literal_t;
  
          public:
              typedef typename detail::term_traits<T>::value_type       value_type;
              typedef typename detail::term_traits<T>::reference        reference;
              typedef typename detail::term_traits<T>::const_reference  const_reference;
  
              literal()
                : base_type(terminal_type::make(T()))
              {}
  
  #ifndef BOOST_NO_CXX11_DEFAULTED_FUNCTIONS
              literal(literal const &) = default;
  #endif
  
              template<typename U>
              literal(U &u)
                : base_type(terminal_type::make(u))
              {}
  
              template<typename U>
              literal(U const &u)
                : base_type(terminal_type::make(u))
              {}
  
              template<typename U>
              literal(literal<U, Domain> const &u)
                : base_type(terminal_type::make(u.get()))
              {}
  
              BOOST_PROTO_EXTENDS_USING_ASSIGN(literal_t)
  
              reference get()
              {
                  return proto::value(*this);
              }
  
              const_reference get() const
              {
                  return proto::value(*this);
              }
          };
      }
  
      /// \brief A helper function for creating a \c literal\<\> wrapper.
      /// \param t The object to wrap.
      /// \return literal\<T &\>(t)
      /// \attention The returned value holds the argument by reference.
      /// \throw nothrow
      template<typename T>
      inline literal<T &> const lit(T &t)
      {
          return literal<T &>(t);
      }
  
      /// \overload
      ///
      template<typename T>
      inline literal<T const &> const lit(T const &t)
      {
          #ifdef BOOST_MSVC
          #pragma warning(push)
          #pragma warning(disable: 4180) // warning C4180: qualifier applied to function type has no meaning; ignored
          #endif
  
          return literal<T const &>(t);
  
          #ifdef BOOST_MSVC
          #pragma warning(pop)
          #endif
      }
  
  }}
  
  #endif