From: nobu@... Date: 2015-12-09T06:31:43+00:00 Subject: [ruby-core:71987] [Ruby trunk - Bug #11793] puts 'ab'.gsub('a', '\\+') - unexpected output Issue #11793 has been updated by Nobuyoshi Nakada. Description updated The document states "It may contain back-references", `\+` is one of them. Note: preformated text requires a preceding blank line. ---------------------------------------- Bug #11793: puts 'ab'.gsub('a', '\\+') - unexpected output https://bugs.ruby-lang.org/issues/11793#change-55396 * Author: William Burnson * Status: Rejected * Priority: Normal * Assignee: * ruby -v: ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-darwin15] * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN ---------------------------------------- Test case: ~~~ruby puts 'ab'.gsub('a', '\\+') ~~~ Expected output: ~~~ \+b ~~~ Actual output: ~~~ b ~~~ The way I understand `gsub(pattern, replacement)` when used with two string arguments is that it will perform a literal replacement, so it is quite unexpected that substituting with `\+` removes the pattern entirely. Doc: http://ruby-doc.org/core-2.2.3/String.html#method-i-gsub -- https://bugs.ruby-lang.org/