Include RE2 library

third_party/re2/util/flags.h

+// Copyright 2009 The RE2 Authors.  All Rights Reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Simplified version of Google's command line flags.
+// Does not support parsing the command line.
+// If you want to do that, see
+// http://code.google.com/p/google-gflags
+
+#ifndef RE2_UTIL_FLAGS_H__
+#define RE2_UTIL_FLAGS_H__
+
+#define DEFINE_flag(type, name, deflt, desc) \
+        namespace re2 { type FLAGS_##name = deflt; }
+
+#define DECLARE_flag(type, name) \
+        namespace re2 { extern type FLAGS_##name; }
+
+#define DEFINE_bool(name, deflt, desc) DEFINE_flag(bool, name, deflt, desc)
+#define DEFINE_int32(name, deflt, desc) DEFINE_flag(int32, name, deflt, desc)
+#define DEFINE_string(name, deflt, desc) DEFINE_flag(string, name, deflt, desc)
+
+#define DECLARE_bool(name) DECLARE_flag(bool, name)
+#define DECLARE_int32(name) DECLARE_flag(int32, name)
+#define DECLARE_string(name) DECLARE_flag(string, name)
+
+#endif  // RE2_UTIL_FLAGS_H__