Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

Sources/OpenVPN3/openvpn/common/to_string.hpp

@@ -0,0 +1,63 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+// Define openvpn::to_string() to work around the fact that
+// std::to_string() is missing on Android.
+// http://stackoverflow.com/questions/22774009/android-ndk-stdto-string-support
+
+#ifndef OPENVPN_COMMON_TO_STRING_H
+#define OPENVPN_COMMON_TO_STRING_H
+
+#include <string>
+#include <sstream>
+#include <type_traits>
+
+#include <openvpn/common/platform.hpp>
+
+namespace openvpn {
+
+  // Convert an arbitrary argument to a string.
+
+#ifndef OPENVPN_PLATFORM_ANDROID
+  // numeric types
+  template <typename T,
+	    typename std::enable_if<std::is_arithmetic<T>::value, int>::type = 0>
+  inline std::string to_string(T value)
+  {
+    return std::to_string(value);
+  }
+#endif
+
+  // non-numeric types
+  template <typename T
+#ifndef OPENVPN_PLATFORM_ANDROID
+	    , typename std::enable_if<!std::is_arithmetic<T>::value, int>::type = 0
+#endif
+	    >
+  inline std::string to_string(const T& value)
+  {
+    std::ostringstream os;
+    os << value;
+    return os.str();
+  }
+}
+
+#endif