Warning C4244: 'argument' : conversion from 'time_t' to 'unsigned int'; possible loss of data in C++

I'm doing a tetris but i seem to have a problem with this

std::mt19937 generator;
generator.seed(std::time(0));
std::uniform_int_distribution<int> pieces(0, 6);
int nCurrtenPiece = pieces(generator);