Mingw32 cross compile with c++11 - c++11

Question

How can I cross compile on Linux for Windows with code that uses C++11 features? So far I've attempted the following:
#include <stdio.h>
class foo
{
public:
const char* getstr() { return "hello world"; }
};
int main()
{
printf("Hello, World!\n");
foo f;
f.getstr();
auto q = f.getstr();
return 0;
}
This fails to build with:
i586-mingw32msvc-g++ cpp11_test.cpp
cpp11_test.cpp: In function ‘int main()’:
cpp11_test.cpp:15: error: ISO C++ forbids declaration of ‘q’ with no type
cpp11_test.cpp:15: error: invalid conversion from ‘const char*’ to ‘int’
No problem I thought, I just need the -std=c++11 option:
i586-mingw32msvc-g++ cpp11_test.cpp -std=c++11
cc1plus: error: unrecognized command line option "-std=c++11"
Still no luck, --version output is:
i586-mingw32msvc-g++ --version
i586-mingw32msvc-g++ (GCC) 4.2.1-sjlj (mingw32-2)
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Is there another option to make this work? Or a new version? How would I get a new version if its not in the package manager, would I have to build a newer compiler from source using the host OS'es compiler?