1 files changed, 80 insertions, 0 deletions
diff --git a/libcxx/test/std/re/re.results/re.results.form/form4.pass.cpp b/libcxx/test/std/re/re.results/re.results.form/form4.pass.cpp
new file mode 100644
index 00000000000..1d44c32f6a8
--- /dev/null
+++ b/libcxx/test/std/re/re.results/re.results.form/form4.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// class match_results<BidirectionalIterator, Allocator>
+
+// string_type
+//   format(const char_type* fmt,
+//          regex_constants::match_flag_type flags = regex_constants::format_default) const;
+
+#include <iostream>
+
+#include <regex>
+#include <cassert>
+
+int main()
+{
+    {
+        std::match_results<const char*> m;
+        const char s[] = "abcdefghijk";
+        assert(std::regex_search(s, m, std::regex("cd((e)fg)hi")));
+
+        const char fmt[] = "prefix: $`, match: $&, suffix: $', m[1]: $1, m[2]: $2";
+        std::string out = m.format(fmt);
+        assert(out == "prefix: ab, match: cdefghi, suffix: jk, m[1]: efg, m[2]: e");
+    }
+    {
+        std::match_results<const char*> m;
+        const char s[] = "abcdefghijk";
+        assert(std::regex_search(s, m, std::regex("cd((e)fg)hi")));
+
+        const char fmt[] = "prefix: $`, match: $&, suffix: $', m[1]: $1, m[2]: $2";
+        std::string out = m.format(fmt, std::regex_constants::format_sed);
+        assert(out == "prefix: $`, match: $cdefghi, suffix: $', m[1]: $1, m[2]: $2");
+    }
+    {
+        std::match_results<const char*> m;
+        const char s[] = "abcdefghijk";
+        assert(std::regex_search(s, m, std::regex("cd((e)fg)hi")));
+
+        const char fmt[] = "match: &, m[1]: \\1, m[2]: \\2";
+        std::string out = m.format(fmt, std::regex_constants::format_sed);
+        assert(out == "match: cdefghi, m[1]: efg, m[2]: e");
+    }
+
+    {
+        std::match_results<const wchar_t*> m;
+        const wchar_t s[] = L"abcdefghijk";
+        assert(std::regex_search(s, m, std::wregex(L"cd((e)fg)hi")));
+
+        const wchar_t fmt[] = L"prefix: $`, match: $&, suffix: $', m[1]: $1, m[2]: $2";
+        std::wstring out = m.format(fmt);
+        assert(out == L"prefix: ab, match: cdefghi, suffix: jk, m[1]: efg, m[2]: e");
+    }
+    {
+        std::match_results<const wchar_t*> m;
+        const wchar_t s[] = L"abcdefghijk";
+        assert(std::regex_search(s, m, std::wregex(L"cd((e)fg)hi")));
+
+        const wchar_t fmt[] = L"prefix: $`, match: $&, suffix: $', m[1]: $1, m[2]: $2";
+        std::wstring out = m.format(fmt, std::regex_constants::format_sed);
+        assert(out == L"prefix: $`, match: $cdefghi, suffix: $', m[1]: $1, m[2]: $2");
+    }
+    {
+        std::match_results<const wchar_t*> m;
+        const wchar_t s[] = L"abcdefghijk";
+        assert(std::regex_search(s, m, std::wregex(L"cd((e)fg)hi")));
+
+        const wchar_t fmt[] = L"match: &, m[1]: \\1, m[2]: \\2";
+        std::wstring out = m.format(fmt, std::regex_constants::format_sed);
+        assert(out == L"match: cdefghi, m[1]: efg, m[2]: e");
+    }
+}