enzyme error when differentiating stateful lambda, but no problems with explicitly defined functor about enzyme HOT 3 CLOSED

change it to (void*)&f like below and its fine:

  double dy = __enzyme_fwddiff<double>((void*)functor_wrapper<decltype(f), std::array<double,2> >, enzyme_const, (void*)&f, enzyme_dup, &x, &dx);

from enzyme.

This is a purely C++ error, outside of Enzyme. Basically its saying that no possible code could definite the definition of enzyme_fwdddiff, since it uses a local variable, and the template is marked extern. However, the compiler actually can definite (as we do here). Marking the type as a non-local type (such as void* in my fix, or your functor in above) means that it's fine.

from enzyme.

Thanks for the quick response-- is there any way to emit a descriptive error message here to help users diagnose this sort of problem and implement your fix?

from enzyme.