g++ option to generate code after template instantiation

[Digvijoy Chatterjee]

when i say std::vector<int> is there an option to  g++ generate
template instantiated source ,before converting C++ to assembly which
could show me how the vector looks.... when the appropriate parameters
are replaced

  template<int, typename _Alloc>
    struct _Vector_base
    {
      struct _Vector_impl
    : public _Alloc {
    int*           _M_start;
    int*           _M_finish;.............


This is a simple example , but if there is such an option this could
be really helpful ,to understand complex template instantiations.

Thx
Digz