GH-1047 parse world files and integrate MCEdit with world page

depends/libnbtplusplus/include/value_initializer.h

@@ -0,0 +1,67 @@
+/*
+ * libnbt++ - A library for the Minecraft Named Binary Tag format.
+ * Copyright (C) 2013, 2015  ljfa-ag
+ *
+ * This file is part of libnbt++.
+ *
+ * libnbt++ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libnbt++ 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef VALUE_INITIALIZER_H_INCLUDED
+#define VALUE_INITIALIZER_H_INCLUDED
+
+#include "value.h"
+
+#include "nbt++_export.h"
+
+namespace nbt
+{
+
+/**
+ * @brief Helper class for implicitly constructing value objects
+ *
+ * This type is a subclass of @ref value. However the only difference to value
+ * is that this class has additional constructors which allow implicit
+ * conversion of various types to value objects. These constructors are not
+ * part of the value class itself because implicit conversions like this
+ * (especially from @c tag&& to @c value) can cause problems and ambiguities
+ * in some cases.
+ *
+ * value_initializer is especially useful as function parameter type, it will
+ * allow convenient conversion of various values to tags on function call.
+ *
+ * As value_initializer objects are in no way different than value objects,
+ * they can just be converted to value after construction.
+ */
+class NBT___EXPORT value_initializer : public value
+{
+public:
+    value_initializer(std::unique_ptr<tag>&& t) noexcept: value(std::move(t)) {}
+    value_initializer(std::nullptr_t) noexcept          : value(nullptr) {}
+    value_initializer(value&& val) noexcept             : value(std::move(val)) {}
+    value_initializer(tag&& t)                          : value(std::move(t)) {}
+
+    value_initializer(int8_t val);
+    value_initializer(int16_t val);
+    value_initializer(int32_t val);
+    value_initializer(int64_t val);
+    value_initializer(float val);
+    value_initializer(double val);
+    value_initializer(const std::string& str);
+    value_initializer(std::string&& str);
+    value_initializer(const char* str);
+};
+
+}
+
+#endif // VALUE_INITIALIZER_H_INCLUDED