[libdevcore] adds Utils.h with small helpers

Author: christianparpart

libdevcore/CMakeLists.txt

@@ -23,6 +23,7 @@ set(sources
 	SwarmHash.h
 	UTF8.cpp
 	UTF8.h
+	Utils.h
 	vector_ref.h
 	Visitor.h
 	Whiskers.cpp

libdevcore/Utils.h

@@ -0,0 +1,44 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity 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 General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+namespace dev
+{
+
+/// Increments @p incrementable and ensures it is getting decremented upon destruction of the returned value.
+///
+/// Use this to ensure scoped increments/decrements in your code.
+template <typename Incrementable>
+auto inline scopedIncrement(Incrementable& incrementable)
+{
+	struct ScopedIncrement {
+		Incrementable& value;
+		~ScopedIncrement() { --value; }
+	};
+	return ScopedIncrement{ ++incrementable };
+}
+
+template <typename Callable>
+auto inline atScopeExit(Callable callable)
+{
+	struct ExitCode {
+		T leave;
+		~ExitCode() { leave(); }
+	};
+	return ExitCode{ std::move(leave) };
+}
+
+} // namespace dev