tree 114217700cb2b1c732235ae6b67a5ae0562cb44d
parent ced82a0501423bdce13210006bf39fe0263f0c24
author Ben Clayton <bclayton@google.com> 1579694402 +0000
committer Ben Clayton <bclayton@google.com> 1579850733 +0000

optional: Remove the value() method that returns non-const-ref.

I'm not convinced that `opt.value() = foo` is a desirable pattern,
and worse still it confuses some compilers about which overload to
use.

Just remove it.