Hello Steven and Matthias, Steven Watanabe wrote:
Yes. The correct solution is to add overloads for the operators, rather than specializations of plain_return_type_2.
template<typename System, typename Dim, typename T> ... operator*(const boost::lambda::lambda_functor<T>&, const boost::units::unit<Dim, System>&);
You'll have to peek at the internals of lambda to figure out what the return type should be.
I finally got around to add the required disambiguation overloads for operator* and operator/ involving boost::units::quantity and boost::units::absolute. All checks in test_lambda.cpp compile and execute now as expected. You can find both files in the attachment. lambda.hpp works also well together with my library of functor wrappers for the cmath functions, which I'm currently working on. However, the latter is still missing some functions from cmath.hpp that's why I haven't included it in this posting. Thus all issues with lambda.hpp known to me are resolved. (Steven suggested to tackle the bind issue of overloaded functions separately.) Do you think this makes the files lambda.hpp, test_lambda.hpp, and lambda.cpp mature enough to become official part of Boost.Units? I'm looking forward to your feedback! Best regards, Torsten