[Boost-users] Using subscript operator with interprocess map

Subject: [Boost-users] Using subscript operator with interprocess map
From: Michi Mutsuzaki (michi_at_[hidden])
Date: 2010-09-07 20:30:01

El 03/09/2010 9:18, Michi Mutsuzaki escribió: 
> char_string needs an allocator in its constructor (not tested code): 

> (*mymap)[char_string("key", alloc_inst)] = 1; 

Thanks Ion, that fixed the compilation error. Now I'm trying create a map 
from char_string to char_string, and that's failing. Here is the code and 
the error message I'm getting (I'm really sorry I keep posting about compilation
errors, but I'm having hard time parsing the error message):

#include <functional>
#include <iostream>
#include <algorithm>
#include <boost/interprocess/managed_mapped_file.hpp>
#include <boost/interprocess/containers/map.hpp>
#include <boost/interprocess/containers/string.hpp>
#include <boost/interprocess/allocators/allocator.hpp>

namespace bi = boost::interprocess;

typedef bi::allocator<char, bi::managed_mapped_file::segment_manager>
        char_alloc;
typedef bi::basic_string<char, std::char_traits<char>, char_alloc>
        char_string;
typedef std::pair<const char_string, char_string> ValueType;
typedef bi::allocator<ValueType, bi::managed_mapped_file::segment_manager>
        map_alloc;
typedef bi::map<char_string, char_string, std::less<char_string>, map_alloc>
        MyMap;

int main ()
{
  bi::managed_mapped_file segment(bi::open_or_create, "/tmp/test", 65536);
  map_alloc alloc_inst (segment.get_segment_manager());
  char_alloc alloc_inst2 (segment.get_segment_manager());
  MyMap *mymap = segment.find_or_construct<MyMap>("MyMap") 
(std::less<char_string>(), alloc_inst);
  (*mymap)[char_string("key", alloc_inst2)] = char_string("val", alloc_inst2);
  return 0;
} 


/usr/local/include/boost/interprocess/containers/map.hpp: In instantiation of 
`T& boost::interprocess::map<Key, T, Pred, Alloc>::operator[](const typename 
boost::interprocess::detail::rbtree<Key, std::pair<const Key, T>, 
boost::interprocess::detail::select1st<std::pair<const Key, T> >, Pred, 
Alloc>::key_type&) [with Key = char_string, T = char_string, Pred = 
std::less<char_string>, Alloc = map_alloc]':
boost_test.cc:27:   instantiated from here
/usr/local/include/boost/interprocess/containers/map.hpp:325: error: no matching 
function for call to `boost::interprocess::allocator<char, 
boost::interprocess::segment_manager<char, 
boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, 
boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index> 
>::allocator()'
/usr/local/include/boost/interprocess/allocators/allocator.hpp:135: note: 
candidates are: boost::interprocess::allocator<T, 
SegmentManager>::allocator(const boost::interprocess::allocator<T, 
SegmentManager>&) [with T = char, SegmentManager = 
boost::interprocess::segment_manager<char, 
boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, 
boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index>]
/usr/local/include/boost/interprocess/allocators/allocator.hpp:130: 
note:                 boost::interprocess::allocator<T, 
SegmentManager>::allocator(SegmentManager*) [with T = char, SegmentManager = 
boost::interprocess::segment_manager<char, 
boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, 
boost::interprocess::offset_ptr<void>, 0u>, boost::interprocess::iset_index>]