First test for marked subexpressions

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@107317 91177308-0d34-0410-b5e6-96231b3b80d8

test/re/re.alg/re.alg.search/basic.pass.cpp

@@ -80,4 +80,48 @@ int main()
         assert(m.position(0) == 1);
         assert(m.str(0) == "ab");
     }
+    {
+        std::cmatch m;
+        const char s[] = "aab";
+        assert(!std::regex_search(s, m, std::regex("ab", std::regex_constants::basic),
+                                            std::regex_constants::match_continuous));
+        assert(m.size() == 0);
+    }
+    {
+        std::cmatch m;
+        const char s[] = "abcd";
+        assert(std::regex_search(s, m, std::regex("bc", std::regex_constants::basic)));
+        assert(m.size() == 1);
+        assert(m.prefix().matched);
+        assert(m.prefix().first == s);
+        assert(m.prefix().second == m[0].first);
+        assert(m.suffix().matched);
+        assert(m.suffix().first == m[0].second);
+        assert(m.suffix().second == s+4);
+        assert(m.length(0) == 2);
+        assert(m.position(0) == 1);
+        assert(m.str(0) == "bc");
+    }
+    {
+        std::cmatch m;
+        const char s[] = "abcdefghijk";
+        assert(std::regex_search(s, m, std::regex("cd\\(\\(e\\)fg\\)hi",
+                                 std::regex_constants::basic)));
+        assert(m.size() == 3);
+        assert(m.prefix().matched);
+        assert(m.prefix().first == s);
+        assert(m.prefix().second == m[0].first);
+        assert(m.suffix().matched);
+        assert(m.suffix().first == m[0].second);
+        assert(m.suffix().second == s+std::regex_traits<char>::length(s));
+        assert(m.length(0) == 7);
+        assert(m.position(0) == 2);
+        assert(m.str(0) == "cdefghi");
+        assert(m.length(1) == 3);
+        assert(m.position(1) == 4);
+        assert(m.str(1) == "efg");
+        assert(m.length(2) == 1);
+        assert(m.position(2) == 4);
+        assert(m.str(2) == "e");
+    }
 }