Earlier versions did use decltype but that causes issues with pointers to member functions. See: https://github.com/progschj/ThreadPool/commit/ac2a77d5cc04361d3

Earlier versions did use decltype but that causes issues with pointers to member functions. See: https://github.com/progschj/ThreadPool/commit/ac2a77d5cc04361d341f63b1d19706a4d1b4943e https://github.com/progschj/ThreadPool/commit/ac2a77d5cc0436... result_of has now been deprecated in newer C++ versions but since this advertises itself as C++11 thread pool I intend to leave it as is.