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_prev_avail:
12// --first is a valid iterator position. When this flag is set the flags
13// match_not_bol and match_not_bow shall be ignored by the regular
14// expression algorithms (30.11) and iterators (30.12)
15
16#include <regex>
17
18#include <cassert>
19#include <string>
20
21int main(int, char**) {
22 char str1[] = "\na";
23 auto str1_scnd = str1 + 1;
24
25 // Assert that match_prev_avail disables match_not_bol and this matches
26 assert(std::regex_match(str1 + 1, str1 + 2, std::regex("^a"),
27 std::regex_constants::match_not_bol |
28 std::regex_constants::match_prev_avail));
29 // Manually passing match_prev_avail defines that --str1 is a valid position
30 assert(std::regex_match(str1_scnd, std::regex("a"),
31 std::regex_constants::match_not_bol |
32 std::regex_constants::match_prev_avail));
33
34 //Assert that match_prev_avail disables match_not_bow and this matches
35 assert(std::regex_search(str1, std::regex("\\ba")));
36 assert(std::regex_match(str1 + 1, str1 + 2, std::regex("\\ba\\b"),
37 std::regex_constants::match_not_bow |
38 std::regex_constants::match_prev_avail));
39 assert(std::regex_search(str1_scnd, std::regex("\\ba"),
40 std::regex_constants::match_not_bow |
41 std::regex_constants::match_prev_avail));
42
43 //Assert that match_prev_avail disables both match_not_bow and match_not_bol
44 assert(std::regex_match(str1 + 1, str1 + 2, std::regex("^a"),
45 std::regex_constants::match_not_bol |
46 std::regex_constants::match_not_bow |
47 std::regex_constants::match_prev_avail));
48 assert(std::regex_match(str1_scnd, std::regex("\\ba"),
49 std::regex_constants::match_not_bol |
50 std::regex_constants::match_not_bow |
51 std::regex_constants::match_prev_avail));
52
53 // pr 42199
54 std::string S = " cd";
55 std::string::iterator Start = S.begin() + 1;
56 std::string::iterator End = S.end();
57 assert(std::regex_search(Start, End, std::regex("^cd")));
58
59 assert(!std::regex_search(Start, End, std::regex("^cd"),
60 std::regex_constants::match_not_bol));
61 assert(!std::regex_search(Start, End, std::regex(".*\\bcd\\b"),
62 std::regex_constants::match_not_bow));
63 assert(!std::regex_search(Start, End, std::regex("^cd"),
64 std::regex_constants::match_not_bol |
65 std::regex_constants::match_not_bow));
66 assert(!std::regex_search(Start, End, std::regex(".*\\bcd\\b"),
67 std::regex_constants::match_not_bol |
68 std::regex_constants::match_not_bow));
69
70 assert(std::regex_search(Start, End, std::regex("^cd"),
71 std::regex_constants::match_prev_avail));
72
73 assert(std::regex_search(Start, End, std::regex("^cd"),
74 std::regex_constants::match_not_bol |
75 std::regex_constants::match_prev_avail));
76 assert(std::regex_search(Start, End, std::regex("^cd"),
77 std::regex_constants::match_not_bow |
78 std::regex_constants::match_prev_avail));
79 assert(std::regex_match(Start, End, std::regex("\\bcd\\b"),
80 std::regex_constants::match_not_bol |
81 std::regex_constants::match_not_bow |
82 std::regex_constants::match_prev_avail));
83 return 0;
84}
85

source code of libcxx/test/std/re/re.const/re.matchflag/match_prev_avail.pass.cpp