https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68863
Bug ID: 68863
Summary: Regular expressions: Backreferences don't work in
negative lookahead
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: allthecoolkidshaveone at gmail dot com
Target Milestone: ---
The following snippet should print out 'false' (And does on perl, javascript,
Microsoft's C++ compiler and everything else I tested on) but instead prints
out 'true' with g++/libstdc++.
#include <iostream>
#include <regex>
int main(void) {
std::cout.setf(std::ios_base::boolalpha);
std::cout << std::regex_match("aa", std::regex("(.)(?!\\1).")) << '\n';
return 0;
}
It appears that backreferences aren't used in lookaheads in the libstdc++ regex
implementation like they should be?
