Error: did not match C++ signature

I'm calling a pyd as follows:
`equity` = calculator.montecarlo({"3H", "3S"}, {"8S", "4S", "QH", "8C", "4H"}, 2, 10000) `

but it complains that the signature is just a set but not a set of strings:
```

EquityCalculatorMontecarlo.montecarlo(set, set, int, int)
did not match C++ signature:
montecarlo(class std::set,class std::allocator >,struct std::less,class std::allocator > >,class std::allocator,class std::allocator > > >, class std::set,class std::allocator >,struct std::less,class std::allocator > >,class std::allocator,class std::allocator > > >, int, int)

Any suggestions what I can do about it?