[encoderer]

Not sure I agree with this logic.

I could easily write a custom Append func in my own application because I would know the Slice types I'm trying to operate on. Writing a language feature is different than writing an application, and it has nothing to do with how trivial something is.

Honestly, Append() as a concept is about as trivial as it gets..

[gnuvince]

> I could easily write a custom Append func in my own application because I would know the Slice types I'm trying to operate on.

More precisely, you would write one custom Append function per Slice type. AppendString, AppendInt, AppendWhatever.

[encoderer]

Yeah, that was supposed to be singular: because I would know the Slice type I'm trying to operate on. Appreciate the clarification. I'll leave the typo there for context.

[loqi]

> Writing a language feature is different than writing an application

True enough. But libraries can easily tend toward either of those extremes. And any obstacles to library development will eventually become obstacles to application development.