• Make exceptions optional
• Fix a variety of errors related to expected<void,E>
• Play nice with CMake's add_subdirectory
• Fix compiling in C++17 mode with a std::invoke visible in the same TU
• Address some compiler warnings
• Remove ordering functions, since they were essentially broken (if you relied on these, please let me know)
• Improve compatibility with tl::optional
• Fix GCC 5.5 support