copy_to_operands(exprt &&) -> add_to_operands

The current name means we end up writing `copy_to_operands(std::move(e))`, which looks like a mistake,
since the whole point is it's a move, not a copy. Instead let's call it `add_to_operands` with
overloads for copying or moving dependent on reference kind.

Author: smowton

src/util/expr.h

@@ -105,13 +105,13 @@ class exprt:public irept
   void reserve_operands(operandst::size_type n)
   { operands().reserve(n) ; }
 
-  DEPRECATED("use copy_to_operands(expr) instead")
+  DEPRECATED("use add_to_operands(expr) instead")
   void move_to_operands(exprt &expr);
 
-  DEPRECATED("use copy_to_operands(e1, e2) instead")
+  DEPRECATED("use add_to_operands(e1, e2) instead")
   void move_to_operands(exprt &e1, exprt &e2);
 
-  DEPRECATED("use copy_to_operands(e1, e2, e3) instead")
+  DEPRECATED("use add_to_operands(e1, e2, e3) instead")
   void move_to_operands(exprt &e1, exprt &e2, exprt &e3);
 
   /// Copy the given argument to the end of `exprt`'s operands.
@@ -121,9 +121,16 @@ class exprt:public irept
     operands().push_back(expr);
   }
 
-  /// Copy the given argument to the end of `exprt`'s operands.
+  /// Add the given argument to the end of `exprt`'s operands.
+  /// \param expr: `exprt` to append to the operands
+  void add_to_operands(const exprt &expr)
+  {
+    copy_to_operands(expr);
+  }
+
+  /// Add the given argument to the end of `exprt`'s operands.
   /// \param expr: `exprt` to append to the operands
-  void copy_to_operands(exprt &&expr)
+  void add_to_operands(exprt &&expr)
   {
     operands().push_back(std::move(expr));
   }
@@ -141,10 +148,18 @@ class exprt:public irept
     op.push_back(e2);
   }
 
-  /// Copy the given arguments to the end of `exprt`'s operands.
+  /// Add the given arguments to the end of `exprt`'s operands.
+  /// \param e1: first `exprt` to append to the operands
+  /// \param e2: second `exprt` to append to the operands
+  void add_to_operands(const exprt &e1, const exprt &e2)
+  {
+    copy_to_operands(e1, e2);
+  }
+
+  /// Add the given arguments to the end of `exprt`'s operands.
   /// \param e1: first `exprt` to append to the operands
   /// \param e2: second `exprt` to append to the operands
-  void copy_to_operands(exprt &&e1, exprt &&e2)
+  void add_to_operands(exprt &&e1, exprt &&e2)
   {
     operandst &op = operands();
     #ifndef USE_LIST
@@ -154,6 +169,15 @@ class exprt:public irept
     op.push_back(std::move(e2));
   }
 
+  /// Add the given arguments to the end of `exprt`'s operands.
+  /// \param e1: first `exprt` to append to the operands
+  /// \param e2: second `exprt` to append to the operands
+  /// \param e3: third `exprt` to append to the operands
+  void add_to_operands(const exprt &e1, const exprt &e2, const exprt &e3)
+  {
+    copy_to_operands(e1, e2, e3);
+  }
+
   /// Copy the given arguments to the end of `exprt`'s operands.
   /// \param e1: first `exprt` to append to the operands
   /// \param e2: second `exprt` to append to the operands
@@ -169,11 +193,11 @@ class exprt:public irept
     op.push_back(e3);
   }
 
-  /// Copy the given arguments to the end of `exprt`'s operands.
+  /// Add the given arguments to the end of `exprt`'s operands.
   /// \param e1: first `exprt` to append to the operands
   /// \param e2: second `exprt` to append to the operands
   /// \param e3: third `exprt` to append to the operands
-  void copy_to_operands(exprt &&e1, exprt &&e2, exprt &&e3)
+  void add_to_operands(exprt &&e1, exprt &&e2, exprt &&e3)
   {
     operandst &op = operands();
     #ifndef USE_LIST

src/util/std_code.h

@@ -149,7 +149,7 @@ class code_blockt:public codet
 
   void add(codet &&code)
   {
-    copy_to_operands(std::move(code));
+    add_to_operands(std::move(code));
   }
 
   void add(codet code, const source_locationt &loc)