tree a2816bf1cbeab2ea796d1b872e38e34b8b7c26f9
parent 80b4bdf5e712d1831a7698a588c62d4d81514c3a
author Marcel van Lohuizen <mpvl@golang.org> 1541532421 +0100
committer Marcel van Lohuizen <mpvl@golang.org> 1543227291 +0000

errors: add support for Is and As methods

An error can implement an Is method to
allow errors to define themselves as being
equal to other errors using the Is function.

An As method can be implemented by errors
for them to pose as another error type using
the As function.

Change-Id: Ib7fcf45acd18d1bca936dbb8c1d075e1a0b62510
Reviewed-on: https://go-review.googlesource.com/c/147877
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>