Introduce ExperimentalFeatures header

libsolidity/ast/ASTAnnotations.h

@@ -23,6 +23,7 @@
 #pragma once
 
 #include <libsolidity/ast/ASTForward.h>
+#include <libsolidity/ast/ExperimentalFeatures.h>
 
 #include <map>
 #include <memory>
@@ -61,8 +62,8 @@ struct SourceUnitAnnotation: ASTAnnotation
 	std::string path;
 	/// The exported symbols (all global symbols).
 	std::map<ASTString, std::vector<Declaration const*>> exportedSymbols;
-	/// Experimental feature pragmas.
-	std::set<ASTString> experimentalFeatures;
+	/// Experimental features.
+	std::set<ExperimentalFeature> experimentalFeatures;
 };
 
 struct ImportAnnotation: ASTAnnotation

libsolidity/ast/ExperimentalFeatures.h

@@ -0,0 +1,35 @@
+/*
+	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/>.
+*/
+/**
+ * List of experimental features.
+ */
+
+#pragma once
+
+#include <map>
+
+namespace dev
+{
+namespace solidity
+{
+
+enum class ExperimentalFeature {};
+
+static const std::map<std::string, ExperimentalFeature> ExperimentalFeatureNames = {};
+
+}
+}