[libcxx] Add "flag" default arg: basic_regex ptr_size_flag ctor

[jasonliu]

Summary

The synopsis in C++11 subclause 28.8 [re.regex] has:

basic_regex(const charT* p, size_t len, flag_type f = regex_constants::ECMAScript);

The default argument is added to libc++ by this change.

[hubert.reinterpretcast]

Minor concerns noted. I'd be okay with this patch, but would like someone else to give the okay (or indicate what issues need to be addressed).

include/regex

148

This line has more than 80 characters; however, the file already has such lines. I guess the libc++ project does not enforce the 80-column policy.

test/std/re/re.regex/re.regex.construct/ptr_size.pass.cpp

31

This appears (like ptr_size_flg.pass.cpp) to neglect testing size in favour of testing flg. Which is to say that, perhaps size should not always be strlen(ptr).

[jasonliu]

Address @hubert.reinterpretcast 's comment about the test case. Added more cases to test "size" parameter in the constructor.

[jasonliu]

test/std/re/re.regex/re.regex.construct/ptr_size.pass.cpp

31

Comment addressed in the new patch. Thanks!

[jasonliu]

Gentle ping?

[hubert.reinterpretcast]

LGTM.

include/regex

public:
     static constexpr regex_constants::syntax_option_type extended = regex_constants::extended;
     static constexpr regex_constants::syntax_option_type awk = regex_constants::awk;
     static constexpr regex_constants::syntax_option_type grep = regex_constants::grep;
     static constexpr regex_constants::syntax_option_type egrep = regex_constants::egrep;
 
     // construct/copy/destroy:
     basic_regex();
     explicit basic_regex(const charT* p, flag_type f = regex_constants::ECMAScript);
-    basic_regex(const charT* p, size_t len, flag_type f);
+    basic_regex(const charT* p, size_t len, flag_type f = regex_constants::ECMAScript);
     basic_regex(const basic_regex&);
     basic_regex(basic_regex&&) noexcept;
     template <class ST, class SA>
         explicit basic_regex(const basic_string<charT, ST, SA>& p,
                              flag_type f = regex_constants::ECMAScript);
     template <class ForwardIterator>
         basic_regex(ForwardIterator first, ForwardIterator last,
                     flag_type f = regex_constants::ECMAScript);
basic_regex()
           __end_(0)
         {}
     _LIBCPP_INLINE_VISIBILITY
     explicit basic_regex(const value_type* __p, flag_type __f = regex_constants::ECMAScript)
         : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
           __end_(0)
         {__parse(__p, __p + __traits_.length(__p));}
     _LIBCPP_INLINE_VISIBILITY
-    basic_regex(const value_type* __p, size_t __len, flag_type __f)
+    basic_regex(const value_type* __p, size_t __len, flag_type __f = regex_constants::ECMAScript)
         : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
           __end_(0)
         {__parse(__p, __p + __len);}
 //     basic_regex(const basic_regex&) = default;
 //     basic_regex(basic_regex&&) = default;
     template <class _ST, class _SA>
         _LIBCPP_INLINE_VISIBILITY
         explicit basic_regex(const basic_string<value_type, _ST, _SA>& __p,

test/std/re/re.regex/re.regex.construct/ptr_size.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <regex>
+
+// template <class charT, class traits = regex_traits<charT>> class basic_regex;
+
+// basic_regex(const charT* p, size_t len);
+
+#include <regex>
+#include <cassert>
+
+template <class CharT>
+void
+test(const CharT* p, std::size_t len, unsigned mc)
+{
+    std::basic_regex<CharT> r(p, len);
+    assert(r.flags() == std::regex_constants::ECMAScript);
+    assert(r.mark_count() == mc);
+}
+
+int main()
+{
+    test("\\(a\\)", 5, 0);
+    test("\\(a[bc]\\)", 9, 0);
+    test("\\(a\\([bc]\\)\\)", 13, 0);
+    test("(a([bc]))", 9, 2);
+   
+    test("(\0)(b)(c)(d)", 12, 4);
+    test("(\0)(b)(c)(d)", 9, 3);
+    test("(\0)(b)(c)(d)", 3, 1);
+    test("(\0)(b)(c)(d)", 0, 0);
+}