std.sumtype?

[Oleg B]

Hello everyone.

Went to see what is being prepared in the new compiler and saw 
this
https://dlang.org/changelog/pending.html#std-sumtype

Is this realy final variant for including to phobos, not 
std.experimental? No way for getting tag explicitly (it's 
private), no way for getting type by tag, sumtype depend on order 
of types... I don't see any discussion about including it to 
phobos... Why? Nobody cares?

I think algebraic types must be in phobos, but it must be fully 
complited. Otherwise it not neccessary: side libs will fix some 
misses and we don't get unified algebraics.

For example std.json have no [de]serialization and vibe.data.json 
is more useful and used in many projects.

More general question: why phobos so bad structured? No way to 
determine what can be used without gc, that need it (other D 
features like betterC in the same situation). Some basic actions 
requires couple of std libs (std.file, std.path etc). Why 
something things placed in experimental will be in experimental 
during several years, other placed to std directly (sumtype)?

May be it's time to restructure std, and determine algorithm for 
place new code to it (like DIPs)?