Boost C++ Libraries

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Boost Pointer Container Library

Class ptr_multimap_adapter

This class is used to build custom pointer containers with an underlying multimap-like container. The interface of the class is an extension of the interface from associative_ptr_container.

Hierarchy:

Navigate:

Synopsis:

namespace boost
{
    template
    < 
        T,
        class VoidPtrMultiMap,
        class CloneAllocator = heap_clone_allocator 
    >
    class ptr_multimap_adapter 
    {
    public: // typedefs
        typedef VoidPtrMap::key_type key_type;
        typedef T*                   mapped_type;
        typedef T&                   mapped_reference;
        typedef const T&             const_mapped_reference;
        typedef ...                  value_type;
        typedef ...                  reference;
        typedef ...                  const_reference;
        typedef ...                  pointer;
        typedef ...                  const_pointer;  
        
    public: // modifiers         
        iterator  insert( key_type& k, T* x ); 
        template< class U >
        iterator  insert( const key_type&, std::auto_ptr<U> x );                        

    public: // pointer container requirements
        void      transfer( iterator object, ptr_multimap_adapter& from );
        size_type transfer( iterator first, iterator last, ptr_multimap_adapter& from );
        template< class Range >
        size_type transfer( const Range& r, ptr_multimap_adapter& from );
        void      transfer( ptr_multimap_adapter& from );

    }; //  class 'ptr_multimap_adapter'

} // namespace 'boost'  

Semantics

. typedefs:

Semantics: typedefs

The following types are implementation defined:

typedef ... value_type;
typedef ... reference;
typedef ... const_reference;
typedef ... pointer;
typedef ... const_pointer;  

However, the structure of the type mimics std::pair s.t. one can use first and second members. The reference-types are not real references and the pointer-types are not real pointers. However, one may still write

map_type::value_type       a_value      = *m.begin();
a_value.second->foo();
map_type::reference        a_reference  = *m.begin();
a_reference.second->foo();
map_type::const_reference  a_creference = *const_begin(m);
map_type::pointer          a_pointer    = &*m.begin();
a_pointer->second->foo();
map_type::const_pointer    a_cpointer   = &*const_begin(m);

The difference compared to std::map<Key,T*> is that constness is propagated to the pointer (that is, to second) in const_itertor.

Semantics: modifiers

  • iterator insert( key_type& k, T* x );

    • Requirements: x != 0
    • Effects: Takes ownership of x and returns an iterator pointing to it.
    • Throws: bad_pointer if x == 0
    • Exception safety: Strong guarantee
  • template< class U > iterator insert( const key_type& k, std::auto_ptr<U> x );

    • Equivalent to (but without the const_cast): return insert( const_cast<key_type&>(k), x.release() );

Semantics: pointer container requirements

  • void transfer( iterator object, ptr_multimap_adapter& from );

    • Requirements: not from.empty()
    • Effects: Inserts the object defined by object into the container and remove it from from.
    • Postconditions: size() is one more, from.size() is one less.
    • Exception safety: Strong guarantee
  • void transfer( iterator first, iterator last, ptr_multimap_adapter& from );

    • Requirements: not from.empty()
    • Effects: Inserts the objects defined by the range [first,last) into the container and remove it from from.
    • Postconditions: Let N == std::distance(first,last); then size() is N more, from.size() is N less.
    • Exception safety: Basic guarantee
  • template< class Range > void transfer( const Range& r, ptr_multimap_adapter& from );

    • Effects: transfer( boost::begin(r), boost::end(r), from );
  • void transfer( ptr_multimap_adapter& from );

    • Effects: transfer( from.begin(), from.end(), from );.
    • Postconditions: from.empty();
    • Exception safety: Basic guarantee

Copyright:Thorsten Ottosen 2004-2006. Use, modification and distribution is subject to the Boost Software License, Version 1.0 (see LICENSE_1_0.txt).