[Boost-users] compile problem using multi_index_container

From: Dwight Kelly (dkelly_at_[hidden])
Date: 2008-02-20 10:35:48

Hello,

I've encountered a problem compiling code that uses boost 
multi_index_container. I'm using both Microsoft Visual Studio 2005 and 
Apple's gcc 4.0.1. Visual Studio was very picky about how I used 
namespaces. I finally got it working with the code below.

The key to success was the 'using namespace boost::multi_index' line. If 
I attempted to prefix the members directly, eg.

typedef typename boost::multi_index::nth_index_const_iterator<0>::type 
left_const_iterator;

or

namespace mi=boost::multi_index;
typedef typename mi::nth_index_const_iterator<0>::type left_const_iterator;

it would fail to compile.

However, when I attempt to compile the same code on Mac OS X using gcc 
4.0.1 I get the following errors. Does anyone know why?

src.cpp:98:error: wrong number of template arguments (1, should be 2)
/boost/boost/multi_index_container_fwd.hpp:46: error: provided for 
'template<class MultiIndexContainer, int N> struct 
boost::multi_index::nth_index_const_iterator'
src.cpp:98: error: expected ';' before 'left_const_iterator'
src.cpp:99: error: wrong number of template arguments (1, should be 2)
/boost/boost/multi_index_container_fwd.hpp:46: error: provided for 
'template<class MultiIndexContainer, int N> struct 
boost::multi_index::nth_index_const_iterator'
src.cpp:99: error: expected ';' before 'right_const_iterator'

-----code----

   using namespace boost::multi_index;

   88      template<class A, class B=String>
   89      class SimpleBiMap : public multi_index_container<
   90          pair<A,B>,
   91          indexed_by<
   92              ordered_unique<member<pair<A,B>, A, 
&pair<A,B>::first> >,
   93              ordered_unique<member<pair<A,B>, B, 
&pair<A,B>::second> >
   94          > >
   95      {
   96      public:
   97          typedef pair<A,B> mytype;
   98          typedef typename nth_index_const_iterator<0>::type 
left_const_iterator;
   99          typedef typename nth_index_const_iterator<1>::type 
right_const_iterator;
  100  
  101          SimpleBiMap(const mytype init[], int N)  {
  102              for (int i=0; i<N; i++)  {
  103                  insert(init[i]);
  104              }
  105          }
  106
  107          left_const_iterator find(const A &key) const  { return 
get<0>().find(key); }
  108          right_const_iterator find(const B &key) const  { return 
get<1>().find(key); }
  109
  110          left_const_iterator left_end() const  { return 
get<0>().end(); }
  111          right_const_iterator right_end() const  { return 
get<1>().end(); }
  112
  113          const B &operator[](const A &key) const  { return 
get<0>().find(key)->second; }
  114          const A &operator[](const B &key) const  { return 
get<1>().find(key)->first; }
  115      };

---code---

Thank you,
Dwight Kelly
Apago, Inc.