Only an implementation in the runtime, by the language, would.

That's false. With anonymous closures you can implement select. See concurrent ML, or https://github.com/twitter/util/blob/develop/util-core/src/m... (which also happens to be lock free)

He's referring to the "select" keyword, which is built into Go. You can't use it with anything other than the built-in channel type.

The great hopac library for F# which is inspired by concurrent ML also supports channels with select.

There now also seems to be an experimental channel implementation for C#/.Net which supports this feature: https://github.com/dotnet/corefxlab/tree/master/src/System.T...