- 
            Boost.PolyCollection has been backported to GCC 4.8 to 4.9 and Clang
            3.3 to 3.6. The version of libstdc++-v3 shipped with GCC 4.8 (which can
            also be used by Clang) has deficiencies that result in the following
            limitations when using Boost.PolyCollection:
            
- 
                  Stateful allocators are not properly supported.
                
- 
                  Allocator-extended move construction decays to allocator-extended
                  copy construction.
                
- 
                  Copy construction crashes if an exception is thrown during element
                  copying.
                
 
- 
            Maintenance fixes.