Bug 19979 – std.regex should return null instead of zero-length slice for non-matched captures

Consider this D program: void main() { auto m = matchFirst("bad", `^(?P<negation>not )?bad$`); assert(m); assert(!m["negation"]); } Currently, the assertion will fail, even though the capture "negation" was not found in the sought string. Ideally, std.regex would return "null" in this circumstance. (Currently, it returns input[0..0], which is a true-ish value.)

@CyberShadow created dlang/phobos pull request #7076 "Fix Issue 19979 - std.regex should return null for non-matched captures" fixing this issue: - Fix Issue 19979 - std.regex should return null for non-matched captures https://github.com/dlang/phobos/pull/7076

dlang/phobos pull request #7076 "Fix Issue 19979 - std.regex should return null instead of zero-length slice for non-matched captures" was merged into master: - 6c5d7230bcf0bf7f00fcc71d775175bfbba0e456 by Vladimir Panteleev: Fix Issue 19979 - std.regex should return null for non-matched captures https://github.com/dlang/phobos/pull/7076