> Go's runtime is written in Go. The whole compiler toolchain, GC, compiler, linker, Assembler, is written in Go.
There's some nuance to this. The runtime code uses specific compiler support and restrictions that are not ordinary Go - possible (or even done, like this case) ≠ ergonomic. No doubt of course that for the Go project, this is still a win.
Do you think libc is also written in pure ISO C?
I love how language extensions, and subsets are always valid for C and C++, but used as an attack against other languages, as if to prove they are not good enough for a specific use case.
Well, neither are C and C++, as they either have to rely on hand written Assembly code, language extensions, or be gutted down into subsets outside the official language standard.