> For example Microsoft's compiler, does not support the C99 standard at all.<p>...in the meantime, restrict is supported in MSVC as regular C keyword, but it took them until VS2019 (specifically compiler version v19.27) - (20 years after the C99 standard was released, and 13 years after this article was written!) while most other important C99 features were "already" (/s) implemented between VS2015 and VS2017.