798   EXPECT_TRUE(MatchRegexAtHead("", ""));  in TEST()
799   EXPECT_TRUE(MatchRegexAtHead("", "ab"));  in TEST()
803   EXPECT_FALSE(MatchRegexAtHead("$", "a"));  in TEST()
805   EXPECT_TRUE(MatchRegexAtHead("$", ""));  in TEST()
806   EXPECT_TRUE(MatchRegexAtHead("a$", "a"));  in TEST()
810   EXPECT_FALSE(MatchRegexAtHead("\\w", "+"));  in TEST()
811   EXPECT_FALSE(MatchRegexAtHead("\\W", "ab"));  in TEST()
813   EXPECT_TRUE(MatchRegexAtHead("\\sa", "\nab"));  in TEST()
814   EXPECT_TRUE(MatchRegexAtHead("\\d", "1a"));  in TEST()
818   EXPECT_FALSE(MatchRegexAtHead(".+a", "abc"));  in TEST()
819   EXPECT_FALSE(MatchRegexAtHead("a?b", "aab"));  in TEST()
821   EXPECT_TRUE(MatchRegexAtHead(".*a", "bc12-ab"));  in TEST()
822   EXPECT_TRUE(MatchRegexAtHead("a?b", "b"));  in TEST()
823   EXPECT_TRUE(MatchRegexAtHead("a?b", "ab"));  in TEST()
828   EXPECT_FALSE(MatchRegexAtHead("\\.+a", "abc"));  in TEST()
829   EXPECT_FALSE(MatchRegexAtHead("\\s?b", "  b"));  in TEST()
831   EXPECT_TRUE(MatchRegexAtHead("\\(*a", "((((ab"));  in TEST()
832   EXPECT_TRUE(MatchRegexAtHead("\\^?b", "^b"));  in TEST()
833   EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "b"));  in TEST()
834   EXPECT_TRUE(MatchRegexAtHead("\\\\?b", "\\b"));  in TEST()
838   EXPECT_FALSE(MatchRegexAtHead("ab.*c", "acabc"));  in TEST()
840   EXPECT_TRUE(MatchRegexAtHead("ab.*c", "ab-fsc"));  in TEST()