epoc32/include/stdapis/boost/iterator/detail/enable_if.hpp
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:27:01 +0100
branchSymbian2
changeset 3 e1b950c65cb4
parent 2 epoc32/include/stdapis/boost/utility/enable_if.hpp@2fe1408b6811
child 4 837f303aceeb
permissions -rw-r--r--
Attempt to represent the S^2->S^3 header reorganisation as a series of "hg rename" operations
     1 // Boost enable_if library
     2 
     3 // Copyright 2003 © The Trustees of Indiana University.
     4 
     5 // Use, modification, and distribution is subject to the Boost Software
     6 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
     7 // http://www.boost.org/LICENSE_1_0.txt)
     8 
     9 //    Authors: Jaakko Järvi (jajarvi at osl.iu.edu)
    10 //             Jeremiah Willcock (jewillco at osl.iu.edu)
    11 //             Andrew Lumsdaine (lums at osl.iu.edu)
    12 
    13 
    14 #ifndef BOOST_UTILITY_ENABLE_IF_HPP
    15 #define BOOST_UTILITY_ENABLE_IF_HPP
    16 
    17 #include "boost/config.hpp"
    18 
    19 // Even the definition of enable_if causes problems on some compilers,
    20 // so it's macroed out for all compilers that do not support SFINAE
    21 
    22 #ifndef BOOST_NO_SFINAE
    23 
    24 namespace boost
    25 {
    26  
    27   template <bool B, class T = void>
    28   struct enable_if_c {
    29     typedef T type;
    30   };
    31 
    32   template <class T>
    33   struct enable_if_c<false, T> {};
    34 
    35   template <class Cond, class T = void> 
    36   struct enable_if : public enable_if_c<Cond::value, T> {};
    37 
    38   template <bool B, class T>
    39   struct lazy_enable_if_c {
    40     typedef typename T::type type;
    41   };
    42 
    43   template <class T>
    44   struct lazy_enable_if_c<false, T> {};
    45 
    46   template <class Cond, class T> 
    47   struct lazy_enable_if : public lazy_enable_if_c<Cond::value, T> {};
    48 
    49 
    50   template <bool B, class T = void>
    51   struct disable_if_c {
    52     typedef T type;
    53   };
    54 
    55   template <class T>
    56   struct disable_if_c<true, T> {};
    57 
    58   template <class Cond, class T = void> 
    59   struct disable_if : public disable_if_c<Cond::value, T> {};
    60 
    61   template <bool B, class T>
    62   struct lazy_disable_if_c {
    63     typedef typename T::type type;
    64   };
    65 
    66   template <class T>
    67   struct lazy_disable_if_c<true, T> {};
    68 
    69   template <class Cond, class T> 
    70   struct lazy_disable_if : public lazy_disable_if_c<Cond::value, T> {};
    71 
    72 } // namespace boost
    73 
    74 #else
    75 
    76 namespace boost {
    77 
    78   namespace detail { typedef void enable_if_default_T; }
    79 
    80   template <typename T>
    81   struct enable_if_does_not_work_on_this_compiler;
    82 
    83   template <bool B, class T = detail::enable_if_default_T>
    84   struct enable_if_c : enable_if_does_not_work_on_this_compiler<T>
    85   { };
    86 
    87   template <bool B, class T = detail::enable_if_default_T> 
    88   struct disable_if_c : enable_if_does_not_work_on_this_compiler<T>
    89   { };
    90 
    91   template <bool B, class T = detail::enable_if_default_T> 
    92   struct lazy_enable_if_c : enable_if_does_not_work_on_this_compiler<T>
    93   { };
    94 
    95   template <bool B, class T = detail::enable_if_default_T> 
    96   struct lazy_disable_if_c : enable_if_does_not_work_on_this_compiler<T>
    97   { };
    98 
    99   template <class Cond, class T = detail::enable_if_default_T> 
   100   struct enable_if : enable_if_does_not_work_on_this_compiler<T>
   101   { };
   102 
   103   template <class Cond, class T = detail::enable_if_default_T> 
   104   struct disable_if : enable_if_does_not_work_on_this_compiler<T>
   105   { };
   106 
   107   template <class Cond, class T = detail::enable_if_default_T> 
   108   struct lazy_enable_if : enable_if_does_not_work_on_this_compiler<T>
   109   { };
   110 
   111   template <class Cond, class T = detail::enable_if_default_T> 
   112   struct lazy_disable_if : enable_if_does_not_work_on_this_compiler<T>
   113   { };
   114 
   115 } // namespace boost
   116 
   117 #endif // BOOST_NO_SFINAE
   118 
   119 #endif