VS2017 already is quite far into supporting C++14/C++17 features, except that expression SFINAE and extended constexpr were not viable to implement on the origi

VS2017 already is quite far into supporting C++14/C++17 features, except that expression SFINAE and extended constexpr were not viable to implement on the original (dated) compiler frontend and therefore the past years have been spent on rewriting large portions of the compiler. The VC team blog provides fairly decent information with regards to reasoning and progress behind this.