tree cb8ad0eb3d7a13f70adbbf961617937896bb3de0
parent 4358cb2f8cb304e64d9a2d2845f472297724e19f
author Chris Kennelly <ckennelly@google.com> 1707756890 -0800
committer Copybara-Service <copybara-worker@google.com> 1707756950 -0800

Add ABSL_ATTRIBUTE_WARN_UNUSED.

This allows us to annotate nontrivial types that should be flagged as unused
variables.  Compilers otherwise ignore nontrivial variables as their
constructors/destructors may be desired and intentional (for example, a scoped
lock).

PiperOrigin-RevId: 606266618
Change-Id: I64b5f6d32a3cec2f18e0aa9029905f5e836c11a9