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diff --git a/libsolidity/interface/EVMVersion.h b/libsolidity/interface/EVMVersion.h
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+/*
+	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/>.
+*/
+/**
+ * EVM versioning.
+ */
+
+#pragma once
+
+#include <string>
+
+#include <boost/optional.hpp>
+#include <boost/operators.hpp>
+
+namespace dev
+{
+namespace solidity
+{
+
+/**
+ * A version specifier of the EVM we want to compile to.
+ * Defaults to the latest version.
+ */
+class EVMVersion:
+	boost::less_than_comparable<EVMVersion>,
+	boost::equality_comparable<EVMVersion>
+{
+public:
+	EVMVersion() {}
+
+	static EVMVersion homestead() { return {Version::Homestead}; }
+	static EVMVersion tangerineWhistle() { return {Version::TangerineWhistle}; }
+	static EVMVersion spuriousDragon() { return {Version::SpuriousDragon}; }
+	static EVMVersion byzantium() { return {Version::Byzantium}; }
+	static EVMVersion constantinople() { return {Version::Constantinople}; }
+
+	static boost::optional<EVMVersion> fromString(std::string const& _version)
+	{
+		for (auto const& v: {homestead(), tangerineWhistle(), spuriousDragon(), byzantium()})
+			if (_version == v.name())
+				return v;
+		return {};
+	}
+
+	bool operator==(EVMVersion const& _other) const { return m_version == _other.m_version; }
+	bool operator<(EVMVersion const& _other) const { return m_version < _other.m_version; }
+
+	std::string name() const
+	{
+		switch (m_version)
+		{
+		case Version::Homestead: return "homestead";
+		case Version::TangerineWhistle: return "tangerineWhistle";
+		case Version::SpuriousDragon: return "spuriousDragon";
+		case Version::Byzantium: return "byzantium";
+		case Version::Constantinople: return "constantinople";
+		}
+		return "INVALID";
+	}
+
+	/// Has the RETURNDATACOPY and RETURNDATASIZE opcodes.
+	bool supportsReturndata() const { return *this >= byzantium(); }
+	bool hasStaticCall() const { return *this >= byzantium(); }
+	bool hasBitwiseShifting() const { return *this >= constantinople(); }
+
+	/// Whether we have to retain the costs for the call opcode itself (false),
+	/// or whether we can just forward easily all remaining gas (true).
+	bool canOverchargeGasForCall() const { return *this >= tangerineWhistle(); }
+
+private:
+	enum class Version { Homestead, TangerineWhistle, SpuriousDragon, Byzantium, Constantinople };
+
+	EVMVersion(Version _version): m_version(_version) {}
+
+	Version m_version = Version::Byzantium;
+};
+
+
+}
+}