v01

thirdparty/Pangolin/include/pangolin/utils/format_string.h

@@ -0,0 +1,87 @@
+/* This file is part of the Pangolin Project.
+ * http://github.com/stevenlovegrove/Pangolin
+ *
+ * Copyright (c) 2014 Hauke Strasdat, Steven Lovegrove
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <sstream>
+
+namespace pangolin {
+namespace details {
+
+// Following: http://stackoverflow.com/a/22759544
+template <typename T>
+class IsStreamable {
+private:
+    template <typename TT>
+    static auto test(int) -> decltype( (std::declval<std::stringstream&>() << std::declval<TT>(), std::true_type()) );
+
+    template <typename>
+    static auto test(...) -> std::false_type;
+
+public:
+    static const bool value = decltype(test<T>(0))::value;
+};
+
+inline void FormatStream(std::stringstream& stream, const char* text)
+{
+    stream << text;
+}
+
+// Following: http://en.cppreference.com/w/cpp/language/parameter_pack
+template <typename T, typename... Args>
+void FormatStream(std::stringstream& stream, const char* text, T arg, Args... args)
+{
+    static_assert(IsStreamable<T>::value,
+                  "One of the args has not an ostream overload!");
+    for (; *text != '\0'; ++text) {
+        if (*text == '%') {
+            stream << arg;
+            FormatStream(stream, text + 1, args...);
+            return;
+        }
+        stream << *text;
+    }
+    stream << "\nFormat-Warning: There are " << sizeof...(Args) + 1
+           << " args unused.";
+}
+
+}  // namespace details
+
+template <typename... Args>
+std::string FormatString(const char* text, Args... args)
+{
+    std::stringstream stream;
+    details::FormatStream(stream, text, args...);
+    return stream.str();
+}
+
+inline std::string FormatString()
+{
+    return std::string();
+}
+
+}