tree f9e1ccd2b8cf1f7b0d7d13ceed7cc0022b0a805d
parent 7e6ffbd038512da5ae7ce06c196764f393990be1
author Filippo Valsorda <filippo@golang.org> 1540745613 -0400
committer Filippo Valsorda <filippo@golang.org> 1540848163 +0000

cryptobyte: add (*Builder).Unwrite and (*Builder).SetError

Unwrite allows programs to rollback builders more reliably and
efficiently than by copying a Builder (which might waste an allocation
and depends on internal behavior). This is useful for example to remove
a length-prefixed field if it ends up being empty.

SetError allows simple Builder extensions to set errors without making
MarshalingValue wrappers.

Based on the experience of CL 144115.

Change-Id: I9a785b81b51b15af49418b5bdb71c4ef222ccc46
Reviewed-on: https://go-review.googlesource.com/c/145317
Reviewed-by: Adam Langley <agl@golang.org>