Add Debugger.TryLoadBool and use it for std::set

Author: awulkiew

solution/GraphicalDebugging/Debugger.cs

@@ -49,6 +49,16 @@ public bool TryLoadDouble(string name, out double result)
             return true;
         }
 
+        public bool TryLoadBool(string name, out bool result)
+        {
+            result = false;
+            Expression expr = debugger.GetExpression("(" + name + ") == true)");
+            if (!expr.IsValidValue)
+                return false;
+            result = (expr.Value == "true" || expr.Value == "1");
+            return true;
+        }
+
         /*struct AddressDifference
         {
             long Value;

solution/GraphicalDebugging/ExpressionLoader_ContainerLoader.cs

@@ -1286,8 +1286,8 @@ public override bool ForEachElement(Debugger debugger, string name, ElementPredi
 
             private bool ForEachElementRecursive(Debugger debugger, string nodeName, ElementPredicate elementPredicate)
             {
-                Expression expr = debugger.GetExpression("(" + nodeName + "->_Isnil == false)");
-                if (expr.IsValidValue && (expr.Value == "true" || expr.Value == "1"))
+                bool isNil;
+                if (debugger.TryLoadBool(nodeName + "->_Isnil", out isNil) && !isNil)
                 {
                     return ForEachElementRecursive(debugger, nodeName + "->_Left", elementPredicate)
                         && elementPredicate(nodeName + "->_Myval")