Replace variadic_function.h with variadic templates.

This time, using forwarding references and not breaking SWIG.

Change-Id: I4069ae960f2d8b1efb79e7cc6f7ba2a7a56d52c0
Reviewed-on: https://code-review.googlesource.com/4882
Reviewed-by: Paul Wankadia <junyer@google.com>
5 files changed