epoc32/include/stdapis/boost/ptr_container/detail/is_convertible.hpp
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:33:34 +0100
branchSymbian3
changeset 4 837f303aceeb
parent 3 e1b950c65cb4
permissions -rw-r--r--
Current Symbian^3 public API header files (from PDK 3.0.h)
This is the epoc32/include tree with the "platform" subtrees removed, and
all but a selected few mbg and rsg files removed.
     1 // (C) Copyright Thorsten Ottosen 2005
     2 // (C) Copyright Howard Hinnant 2004
     3 // (C) Copyright Jonathan Turkanis 2004
     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 //
     8 // Contains type traits machinery for incomplete arrays. MPL compatibility
     9 // is included for completeness, but is not necessary for the current 
    10 // application.
    11 // 
    12 
    13 #ifndef BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED
    14 #define BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED
    15 
    16 #include <boost/config.hpp> // BOOST_STATIC_CONSTANT.
    17 #include <boost/mpl/aux_/lambda_support.hpp>
    18 #include <boost/mpl/and.hpp>
    19 #include <boost/mpl/bool.hpp>
    20 #include <boost/mpl/identity.hpp>
    21 #include <boost/mpl/if.hpp>
    22 #include <boost/type_traits/is_array.hpp>
    23 #include <boost/type_traits/is_convertible.hpp>
    24 #include <boost/type_traits/is_same.hpp>
    25 #include <boost/type_traits/remove_bounds.hpp>
    26 #include <boost/type_traits/remove_cv.hpp>
    27 #include <boost/utility/enable_if.hpp>
    28 
    29 namespace boost { namespace ptr_container_detail { namespace move_ptrs {
    30 
    31 // From Howard Hinnant.
    32 template<typename T, typename U>
    33 struct is_array_convertible {
    34     typedef typename remove_bounds<T>::type      t_element; 
    35     typedef typename remove_bounds<U>::type      u_element; 
    36     typedef typename remove_cv<t_element>::type  t_base; 
    37     typedef typename remove_cv<u_element>::type  u_base; 
    38     typedef typename 
    39             mpl::and_<
    40                 is_array<T>,
    41                 is_array<U>,
    42                 is_same<t_base, u_base>,
    43                 is_convertible<t_element*, u_element*>
    44             >::type                                     type;
    45     BOOST_STATIC_CONSTANT(bool, value = type::value);
    46     BOOST_MPL_AUX_LAMBDA_SUPPORT(2, is_array_convertible, (T, U))
    47 };
    48 
    49 template<typename T, typename U>
    50 struct is_smart_ptr_convertible 
    51     : mpl::if_<
    52           is_array<T>,
    53           is_array_convertible<T, U>,
    54           is_convertible<T*, U*> 
    55       >::type
    56     { };
    57 
    58 #ifndef BOOST_NO_SFINAE
    59     template<typename Src, typename Tgt, typename T = void>
    60     struct enable_if_convertible 
    61         : enable_if< 
    62               is_smart_ptr_convertible<Src, Tgt>,
    63               T
    64           >
    65         { };
    66 #else
    67     template<typename Src, typename Tgt, class T >
    68     struct enable_if_convertible : mpl::identity<T> { };
    69 #endif
    70 
    71 } } }         // End namespaces ptr_container_detail, move_ptrs, boost.
    72 
    73 #endif      // #ifndef BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED