Given the following simple code snippet, tested on x86_64-pc-linux-gnu,
i686-pc-linux-gnu, and i686-pc-mingw32:

<<
struct Elem {
   int data;
   struct Elem* next;
};

int main () {
   struct Elem* list;
   return 0;
}
>>

Compile with:
g++ main.cc -o main

run under gdb:
gdb main
ptype Elem

yields:
type = struct Elem {
    int data;
    void *next;
}

instead of (with e.g. g++ 4.4.3):
type = struct Elem {
    int data;
    Elem *next;
}