References, Mutable References, Moves/Copies

[sunjay]

Reference: &Foo
Mutable reference: &mut Foo
Move/Copy: Foo

The data should be moved if type does not implement Copy, copy otherwise.

• Fix all variables are mutable references All Variables Are Mutable References #67
• Consider making variables immutable by default and add a mut keyword
  • This may not constitute a major semver change depending on the breaking impact
• Static analysis should prevent using a value after it has been moved
  • Could start by not supporting moves if the static analysis isn't mature enough yet (this would mean non-copy types would always have to be passed by reference--not bad)
• Automatic referencing/dereferencing