ceph/src/boost/libs/config/test/boost_no_using_breaks_adl.ipp

   1 //  (C) Copyright John Maddock 2001.
   2 //  Use, modification and distribution are subject to the
   3 //  Boost Software License, Version 1.0. (See accompanying file
   4 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //  See http://www.boost.org/libs/config for most recent version.
   7
   8 //  MACRO:         BOOST_FUNCTION_SCOPE_USING_DECLARATION_BREAKS_ADL
   9 //  TITLE:         broken ADL
  10 //  DESCRIPTION:   Using declarations break argument dependent lookup
  11 //                 (probably Borland specific), the fix is to use
  12 //                 using namespace whatever; rather than
  13 //                 using whatever::symbol;.
  14
  15
  16 namespace boost_ns
  17 {
  18    template <class T>
  19    T* get_pointer(T* p)
  20    { return p; }
  21
  22    namespace inner2
  23    {
  24       template <class T>
  25       struct X {};
  26
  27       template <class T>
  28       T* get_pointer(X<T>)
  29       { return 0; }
  30    }
  31 }
  32
  33 namespace user_ns
  34 {
  35    template <class T>
  36    struct Y{};
  37
  38    template <class T>
  39    T* get_pointer(user_ns::Y<T>)
  40    { return 0; }
  41
  42    template <class T>
  43    int f(T x)
  44    {
  45       // use this as a workaround:
  46       //using namespace boost;
  47       // this statement breaks ADL:
  48       using boost_ns::get_pointer;    // conforming compilers require
  49                                    // this one to find the auto_ptr
  50                                    // and T* overloads
  51       return get_pointer(x) == 0;
  52    }
  53 }
  54
  55 namespace boost_function_scope_using_declaration_breaks_adl{
  56
  57 int test()
  58 {
  59    int i;
  60    typedef void* pv;
  61    i = user_ns::f(pv());
  62    i = user_ns::f(boost_ns::inner2::X<int>());
  63    (void)i;
  64    return 0;
  65 }
  66
  67 }
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