- introduce the concept of qualifiers on l-value types
- teach overload resolution and coercion how to drop explicitness
- require explicitness on normal [byref] arguments
- make 'this' [byref(implicit)]
- special-case '&' as a unary operator in the parser to make it
produce an expression which type-checks as turning implicit l-values
into explicit ones.
Obvious missing pieces:
- updating LangRef
- we should really complain about ever trying to rvalue-convert an
explicit l-value
- maybe qualification should play a part in overload resolution
- we should diagnose attempts to declare unary '&' operators
- there's a test case in expressions.swift which suggests my logic is
slightly off
But I am out of time, and these will have to wait.
Swift SVN r1119
it doesn't appear in places it shouldn't. The only limits on
this checking right now is the inadequacy of location information
for types, which is something we ought to fix.
Fix type-checking of byref applications. Fix IR generation
of byref variables. Whole lotta fixin' goin' on.
But hey, byref calls work.
Swift SVN r1111
