tree f1453ffb67b01422840f98512f751bb2e37f519d
parent 18c78fc62662b7003232e00b360dc1748e4ef3b2
author Andrew Scull <ascull@google.com> 1534770568 +0100
committer Andrew Scull <ascull@google.com> 1534770568 +0100

Switch from include guard to pragma once.

This pragma is so widley supported it is a defacto standard. It has the
advantage over include guards in that a unique macro identifier does not
need to be created and maintained.

Change-Id: Id12f56d9970fdfb63d45c92e428d3dbe44b2ab0e