init keyword to replace new keyword

[Thaina]

I see init was made to be contextual keyword as of C# 9. I think maybe we should let it be full fledge keyword. And replace the new keyword for object construction

It could be made to be transpile wrapper mechanism, underlyingly transform into new / calling generated static factory Create method / and fabriate anything so this could also solving

• async constructor Discussion: async constructors #419
• Defer constructor Defer constructor #2722 (also Defer constructor #2722 (comment))

and some other proposed feature could be included without any disturbing the older repo