tree 2c54c47970ef0de9529db601500f3e398fbde449
parent 2d15272e8145f7e68faea4652fb5e5049f19cca9
author Paul Wankadia <junyer@google.com> 1552896298 -0700
committer Paul Wankadia <junyer@google.com> 1552896556 +0000

Get rid of `using std::string;`. (part 3 of N)

Change-Id: I24c9a04ba92ec6503bb040658f07e7aabacf74f2
Reviewed-on: https://code-review.googlesource.com/c/re2/+/39114
Reviewed-by: Paul Wankadia <junyer@google.com>