If you are using GCC, Clang, or MSVC then the standards support is excellent[1]. But putting that aside > For those languages you wouldn't consider a feature

If you are using GCC, Clang, or MSVC then the standards support is excellent[1]. But putting that aside > For those languages you wouldn't consider a feature added until it was supported by the reference compiler Well, there is no reference compiler for C++. I don't think any language with either an ISO or ECMA standard has a reference compiler or interpreter. There are gaps in support here in and there. But I would still say those mainstream compilers "support" C++17 for the same reason I would say that Chrome "supports" CSS3, despite it not implementing the full specification. [1] https://en.cppreference.com/w/cpp/compiler_support https://en.cppreference.com/w/cpp/compiler_support