Jonathan B. Coe

Make null-state non-observable

3

Work in progress, does not compile.

See https://github.com/carbon-language/carbon-lang/blob/trunk/common/indirect_value.h

Add a GDB pretty-printer

1

See: https://sourceware.org/gdb/onlinedocs/gdb/Pretty-Printing.html

Ensure that indirect_value can be passed in a register when the copier/deleter are empty

1

See: https://stackoverflow.com/questions/58339165/why-can-a-t-be-passed-in-register-but-a-unique-ptrt-cannot for more context.

Make null-state non-observable

3

Make default constructor private. Make null-state only accessible via a move. Replace operator bool with valueless_by_move.