type simplify_unary_plus

This improves type safety.

Author: kroening

src/util/simplify_expr.cpp

@@ -2214,7 +2214,7 @@ bool simplify_exprt::simplify_node(exprt &expr)
   }
   else if(expr.id()==ID_unary_plus)
   {
-    r = simplify_unary_plus(to_unary_expr(expr));
+    r = simplify_unary_plus(to_unary_plus_expr(expr));
   }
   else if(expr.id()==ID_not)
   {

src/util/simplify_expr_class.h

@@ -59,6 +59,7 @@ class tvt;
 class typecast_exprt;
 class unary_exprt;
 class unary_minus_exprt;
+class unary_plus_exprt;
 
 #define forall_value_list(it, value_list) \
   for(simplify_exprt::value_listt::const_iterator it=(value_list).begin(); \
@@ -172,7 +173,7 @@ class simplify_exprt
   NODISCARD resultt<> simplify_good_pointer(const unary_exprt &);
   NODISCARD resultt<> simplify_object(const exprt &);
   NODISCARD resultt<> simplify_unary_minus(const unary_minus_exprt &);
-  NODISCARD resultt<> simplify_unary_plus(const unary_exprt &);
+  NODISCARD resultt<> simplify_unary_plus(const unary_plus_exprt &);
   NODISCARD resultt<> simplify_dereference(const dereference_exprt &);
   NODISCARD resultt<> simplify_address_of(const address_of_exprt &);
   NODISCARD resultt<> simplify_pointer_offset(const unary_exprt &);

src/util/simplify_expr_int.cpp

@@ -1111,7 +1111,7 @@ simplify_exprt::simplify_extractbits(const extractbits_exprt &expr)
 }
 
 simplify_exprt::resultt<>
-simplify_exprt::simplify_unary_plus(const unary_exprt &expr)
+simplify_exprt::simplify_unary_plus(const unary_plus_exprt &expr)
 {
   // simply remove, this is always 'nop'
   return expr.op();