Thunking std::function objects

[MeanSquaredError]

Thank you for the useful library.

Not really an issue, just an observation that with C++11 and templates the library can be expanded to allow thunks to arbitrary std::function objects.

[yiz6688]

Thank you for the useful library.

Not really an issue, just an observation that with C++11 and templates the library can be expanded to allow thunks to arbitrary std::function objects.

std::function can not convert to c style function you have to pass this pointer yourself

[MeanSquaredError]

@yiz6688 std::function does not need to convert to a C-style function. The purpose of the thunking library is to perform that conversion.