#1 incompability with 64 bit architecture

[Kambiz Veshgini]

On linux amd64 I get the compilation error:
"src/../include/impl/shared_ptr.hpp:15: error: cast from 'const void*' to 'unsigned int' loses precision"

shared_ptr.hpp:

12 size_t operator () (const void * const v) const
13 {
14 static __gnu_cxx::hash<unsigned int> H;
15 return H((unsigned int)v);
16 }

Replacing "unsigned int" with "size_t" seems to solve the problem.