libcxx/test/std/re/re.const/re.matchflag/match_not_null.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <regex>
  10
  11 // match_not_null:
  12 //     The regular expression shall not match an empty sequence.
  13
  14 #include "test_macros.h"
  15 #include <cassert>
  16 #include <regex>
  17
  18 int main(int, char**)
  19 {
  20   // When match_not_null is on, the regex engine should reject empty matches and
  21   // move on to try other solutions.
  22   std::cmatch m;
  23   assert(!std::regex_search("a", m, std::regex("b*"),
  24                             std::regex_constants::match_not_null));
  25   assert(std::regex_search("aa", m, std::regex("a*?"),
  26                            std::regex_constants::match_not_null));
  27   assert(m[0].length() == 1);
  28   assert(!std::regex_search("a", m, std::regex("b*", std::regex::extended),
  29                             std::regex_constants::match_not_null));
  30   assert(!std::regex_search(
  31       "a", m,
  32       std::regex("b*", std::regex::extended | std::regex_constants::nosubs),
  33       std::regex_constants::match_not_null));
  34
  35   assert(!std::regex_match("", m, std::regex("a*"),
  36                            std::regex_constants::match_not_null));
  37   assert(!std::regex_match("", m, std::regex("a*", std::regex::extended),
  38                            std::regex_constants::match_not_null));
  39   assert(!std::regex_match(
  40       "", m,
  41       std::regex("a*", std::regex::extended | std::regex_constants::nosubs),
  42       std::regex_constants::match_not_null));
  43
  44   return 0;
  45 }