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diff --git a/tiger-compiler/lib/misc/endomap.hh b/tiger-compiler/lib/misc/endomap.hh
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+++ b/tiger-compiler/lib/misc/endomap.hh
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+/**
+ ** \file misc/endomap.hh
+ ** \brief Declaration of misc::endomap.
+ */
+
+#pragma once
+
+#include <list>
+#include <map>
+
+#include <misc/map.hh>
+
+namespace misc
+{
+  /** \brief A renaming mapping defaulting to identity:
+      Mapping a class with itself (endomorphism).
+      Unless a value is already mapped onto another, map it to itself
+      if nonstrict. This is a special case of std::map. */
+  template <class T> class endomap : public map<T, T>
+  {
+  public:
+    /// Super class type.
+    using super_type = map<T, T>;
+
+    // Import overloaded virtual functions.
+    using super_type::operator[];
+    using super_type::operator();
+
+    enum class strictness_type
+    {
+      /// Querying about an unknown identifier returns itself.
+      nonstrict,
+      /// Querying about an unknown identifier is an error.
+      strict
+    };
+
+    /// \name Constructors and destructor.
+    /// \{
+    endomap();
+    /// \}
+
+    /// Return a duplicate of \a this.
+    endomap* clone() const override;
+
+    /// Return a reference to the value associated to \a t.
+    ///
+    /// If \a t was not inserted before, then, contrary to std::map,
+    /// we insert t -> t into the map, instead of `t -> T()'.  This
+    /// spares the construction of a new T, which may have nasty
+    /// effects if this constructor has side effects (e.g.,
+    /// incrementing a counter).
+    virtual T& operator[](const T& t);
+
+    /// Lookup for \a t, returning it if unknown.
+    T operator()(const T& t) const override;
+
+  protected:
+    /// If strict, queries for an unknown (unmapped) Identifier is an error.
+    strictness_type strictness_;
+  };
+
+} // namespace misc
+
+#include <misc/endomap.hxx>