升压进程间地图int和string

Question

我有下面的代码，使用升压进程间

using namespace boost::interprocess; 
//Shared memory front-end that is able to construct objects 
//associated with a c-string. Erase previous shared memory with the name 
//to be used and create the memory segment at the specified address and initialize resources 
shared_memory_object::remove("MySharedMemory"); 

try{ 
    managed_shared_memory segment 
     (create_only 
     ,"MySharedMemory" //segment name 
     ,655360);   //segment size in bytes 

    //Note that map<Key, MappedType>'s value_type is std::pair<const Key, MappedType>, 
    //so the allocator must allocate that pair. 
    typedef allocator<char, managed_shared_memory::segment_manager> CharAllocator; 
    typedef basic_string<char, std::char_traits<char> ,CharAllocator> MyShmString; 
    typedef allocator<MyShmString, managed_shared_memory::segment_manager> StringAllocator; 

    typedef int KeyType; 
    typedef std::pair<const int, StringAllocator> ValueType; 
    typedef StringAllocator MappedType; 

    typedef allocator<ValueType, managed_shared_memory::segment_manager> ShmemAllocator; 

    typedef map<KeyType, MappedType, std::less<KeyType>, ShmemAllocator> MyMap; 

    //Initialize the shared memory STL-compatible allocator 
    ShmemAllocator alloc_inst (segment.get_segment_manager()); 
    CharAllocator charallocator (segment.get_segment_manager()); 


    //Construct a shared memory map. 
    //Note that the first parameter is the comparison function, 
    //and the second one the allocator. 
    //This the same signature as std::map's constructor taking an allocator 
    MyMap *mymap = 
     segment.construct<MyMap>("MyMap")  //object name 
     (std::less<int>() //first ctor parameter 
     ,alloc_inst);  //second ctor parameter 

    //Insert data in the map 
    MyShmString mystring(charallocator); 
    mystring = "this is my text"; 
    for(int i = 0; i < 100; ++i){ 
     //mymap[i] = mystring; 
     mymap->insert(std::pair<const int, MappedType>(i, mystring)); 
    } 
} 

这段代码犯规编译节省了地图到共享内存..它引发以下错误

no matching function for call to ‘std::pair<const int, boost::interprocess::allocator<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >::pair(int&, main()::MyShmString&)’ 
    /usr/include/c++/4.2.1/bits/stl_pair.h:84: note: candidates are: std::pair<_T1, _T2>::pair(const _T1&, const _T2&) [with _T1 = const int, _T2 = boost::interprocess::allocator<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> >] 
    /usr/include/c++/4.2.1/bits/stl_pair.h:80: note:     std::pair<_T1, _T2>::pair() [with _T1 = const int, _T2 = boost::interprocess::allocator<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> >] 
    /usr/include/c++/4.2.1/bits/stl_pair.h:69: note:     std::pair<const int, boost::interprocess::allocator<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >::pair(const std::pair<const int, boost::interprocess::allocator<boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void>, 0ul>, boost::interprocess::iset_index> > >&) 

区别如果

::pair(int&, main()::MyShmString&) 

所以我猜

  mymap->insert(std::pair<const int, MappedType>(i, mystring)); 

是不是正确的方式去..所以我应该如何插入到地图，如果错误是有..其他什么是错误？

Answer 1

肯定的是VALUE_TYPE：

typedef std::pair<const int, MyShmString > ValueType; 

不

typedef std::pair<const int, StringAllocator> ValueType; 

而且类似：

typedef MyShmString MappedType; 

不

typedef StringAllocator MappedType; 

Answer 2

您的类型不同，是故意的吗？ MyShmString是不一样的MappedType - 可能是你应该更改以下行：

typedef StringAllocator MappedType; 

到

typedef MyShmString MappedType;