Why do I get the same sequence from std::random_device with MinGW GCC 4.8.1?

In the provided code, an instance of std::random_device (rd) is used as the seed for a Mersenne Twister engine (mt). However, the observed behavior of obtaining the same sequence of random numbers with every run suggests that the rd may not be providing a truly random seed.

According to the documentation (http://en.cppreference.com/w/cpp/numeric/random/random_device), std::random_device is designed to access non-deterministic hardware sources for randomness. However, if such a source is unavailable, the implementation may resort to a pseudo-random number engine. This could explain the deterministic behavior observed with MinGW GCC 4.8.1.

It is important to note that random_device is not guaranteed to provide true randomness. Some implementations, like the one in MinGW GCC 4.8.1, may deliberately deliver a fixed sequence to demonstrate the non-randomness of the stream.

To obtain different output for each run, one should consider alternative methods of seeding the random number generator, such as using a seed based on the current time or a cryptographic hash of some user input.