diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 601b249e6..21c0b8c91 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -23,6 +23,8 @@ add_executable(yul-phaser
yulPhaser/FitnessMetrics.cpp
yulPhaser/Chromosome.h
yulPhaser/Chromosome.cpp
+ yulPhaser/Selections.h
+ yulPhaser/Selections.cpp
yulPhaser/Program.h
yulPhaser/Program.cpp
yulPhaser/SimulationRNG.h
diff --git a/tools/yulPhaser/Selections.cpp b/tools/yulPhaser/Selections.cpp
new file mode 100644
index 000000000..19451f45c
--- /dev/null
+++ b/tools/yulPhaser/Selections.cpp
@@ -0,0 +1,18 @@
+/*
+ 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 .
+*/
+
+#include
diff --git a/tools/yulPhaser/Selections.h b/tools/yulPhaser/Selections.h
new file mode 100644
index 000000000..1155c6708
--- /dev/null
+++ b/tools/yulPhaser/Selections.h
@@ -0,0 +1,52 @@
+/*
+ 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 .
+*/
+/**
+ * Contains an abstract base class representing a selection of elements from a collection
+ * and its concrete implementations.
+ */
+
+#pragma once
+
+#include
+
+namespace solidity::phaser
+{
+
+/**
+ * Abstract base class for selections of elements from a collection.
+ *
+ * An instance of this class represents a specific method of selecting a set of elements from
+ * containers of arbitrary sizes. The set of selected elements is always a subset of the container
+ * but may indicate the same element more than once. The selection may or may not be fixed - it's
+ * up to a specific implementation whether subsequent calls for the same container produce the same
+ * indices or not.
+ *
+ * Derived classes are meant to override the @a materialise() method.
+ * This method is expected to produce indices of selected elements given the size of the collection.
+ */
+class Selection
+{
+public:
+ Selection() = default;
+ Selection(Selection const&) = delete;
+ Selection& operator=(Selection const&) = delete;
+ virtual ~Selection() = default;
+
+ virtual std::vector materialise(size_t _poolSize) const = 0;
+};
+
+}