Why are some types from std not in the core of the language?

[monkyyy]

On Friday, 10 June 2022 at 01:08:02 UTC, mesni wrote:
> D has AA and arrays built into the language and runtime. But 
> why are sumtype, arrays/smart pointers using custom allocators, 
> nullable, tuple at the expense of std? Everything listed in 
> this article https://dlang.org/articles/builtin.html applies to 
> them. I think this can be done as something like an optional 
> extension in the compiler.

So everyone can feel extremely clever coding their own with 
recursive templates

Also generally speaking the apis people pick for these things are 
awful, I rather have more meta programming tools