Filippo Valsorda
b078efbc80
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>