Martin Moene (my favorite C++ person in the entire universe right now) wrote a drop-in replacement for older standard versions: https://github.com/martinmoene/string-view-lite. He's also backported optional, variant, and expected, and wrote my favorite unit testing library called "lest".

This guy saved me so much hassle this year and it's causing a complete sea change in the way that we work. I really really want to live in a world of value-typedness and it's finally possible to do it. The simple and natural idioms are now MORE efficient than doing it the complicated way: the average function I'm writing in 2018 is significantly less convoluted and allocates on the heap far less than the same function I'd be writing five or six years ago.

Yes, but the final version of the C++17 standard was released as late as December 2017, so support may not be "production ready", neither in gcc nor in other compilers.

You can the summary of the gcc c++ standard support here: https://gcc.gnu.org/projects/cxx-status.html#cxx17. Full support for all features in the c++17 standard, but the support is declared "experimental".

Similarly here for clang: https://clang.llvm.org/cxx_status.html

And Visual studio: https://blogs.msdn.microsoft.com/vcblog/2018/04/26/announcin... (link to latest blog post, perhaps there is a status page that gets updated, but could not find it).