Why can't someone make a language where you can optionally use GC on one chunk of memory and use automated reference counting on another chunk? Tell the compil

Why can't someone make a language where you can optionally use GC on one chunk of memory and use automated reference counting on another chunk? Tell the compiler which variables should be in which category, and then most of the quick programming is done in GC while all the stuff that needs to be performant will be in reference counting but automatically managed so you shouldn't have to know outside of the one keyword to flag the variable and occasionally breaking a cycle when you want to free a structure (or using weak references like Obj-C allows).