How can I borrow with conditional binding?

[dnadoba (David Nadoba)]

Yeah, I think you want if inout foo = &foo as proposed in Pitch: `borrow` and `inout` declaration keywords which isn't available yet. (Or I guess behind the ReferenceBindings experimental feature @dmt mentioned?)

The alternative @jameesbrown provided is your best option today:

@jameesbrown

    if var foo = foo.take() {
      // mutate the wrapped value while uniquely referencing.
      foo.baz = 3
      // move back into self.foo.
      self.foo = consume foo
    }