Why do I get the same sequence for every run with std::random_device with mingw gcc4.8.1?

From http://en.cppreference.com/w/cpp/numeric/random/random_device:

Note that std::random_device may be implemented in terms of a pseudo-random number engine if a non-deterministic source (e.g. a hardware device) is not available to the implementation.

I would expect a decent implementation to at least seed the RNG though.

Edit: I suspect they deliberately chose to deliver the same sequence each time, to make obvious the fact that the stream wasn't as random as promised.

I got a confirmed answer from STL from MSFT:

Unlike VC, GCC hasn't implemented random_device nondeterministically on Windows. Boost has, so you can use Boost.Random.

You may need to pass a parameter to the constructor:

https://gcc.gnu.org/onlinedocs/gcc-4.9.1/libstdc++/api/a00899.html