isVariableReassignment for ++ and --

idea/src/org/jetbrains/jet/lang/resolve/BindingContext.java

@@ -41,7 +41,7 @@ public interface BindingContext {
     boolean isStatement(JetExpression expression);
     boolean hasBackingField(PropertyDescriptor propertyDescriptor);
 
-    boolean isVariableReassignment(JetBinaryExpression expression);
+    boolean isVariableReassignment(JetExpression expression);
 
     ConstructorDescriptor resolveSuperConstructor(JetDelegatorToSuperCall superCall);
 

idea/src/org/jetbrains/jet/lang/resolve/BindingTrace.java

@@ -29,7 +29,7 @@ public interface BindingTrace {
 
     void recordStatement(@NotNull JetElement statement);
 
-    void recordVariableReassignment(@NotNull JetBinaryExpression expression);
+    void recordVariableReassignment(@NotNull JetExpression expression);
 
     void recordResolutionScope(@NotNull JetExpression expression, @NotNull JetScope scope);
 

idea/src/org/jetbrains/jet/lang/resolve/BindingTraceAdapter.java

@@ -58,7 +58,7 @@ public class BindingTraceAdapter implements BindingTrace {
     }
 
     @Override
-    public void recordVariableReassignment(@NotNull JetBinaryExpression expression) {
+    public void recordVariableReassignment(@NotNull JetExpression expression) {
         originalTrace.recordVariableReassignment(expression);
     }
 

idea/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java

@@ -31,7 +31,7 @@ public class BindingTraceContext implements BindingContext, BindingTrace {
     private final Map<JetExpression, JetType> autoCasts = Maps.newHashMap();
     private final Map<JetExpression, JetScope> resolutionScopes = Maps.newHashMap();
 
-    private final Set<JetBinaryExpression> variableReassignments = Sets.newHashSet();
+    private final Set<JetExpression> variableReassignments = Sets.newHashSet();
 
     private final Set<JetFunctionLiteralExpression> blocks = new HashSet<JetFunctionLiteralExpression>();
     private final Set<JetElement> statements = new HashSet<JetElement>();
@@ -163,7 +163,7 @@ public class BindingTraceContext implements BindingContext, BindingTrace {
     }
 
     @Override
-    public void recordVariableReassignment(@NotNull JetBinaryExpression expression) {
+    public void recordVariableReassignment(@NotNull JetExpression expression) {
         variableReassignments.add(expression);
     }
 
@@ -308,7 +308,7 @@ public class BindingTraceContext implements BindingContext, BindingTrace {
     }
 
     @Override
-    public boolean isVariableReassignment(JetBinaryExpression expression) {
+    public boolean isVariableReassignment(JetExpression expression) {
         return variableReassignments.contains(expression);
     }
 

idea/src/org/jetbrains/jet/lang/types/JetTypeInferrer.java

@@ -2167,12 +2167,15 @@ public class JetTypeInferrer {
                         JetType returnType = functionDescriptor.getReturnType();
                         if (operationType == JetTokens.PLUSPLUS || operationType == JetTokens.MINUSMINUS) {
                             if (semanticServices.getTypeChecker().isSubtypeOf(returnType, JetStandardClasses.getUnitType())) {
-                                 result = JetStandardClasses.getUnitType();
+                                result = JetStandardClasses.getUnitType();
                             }
                             else {
                                 if (!semanticServices.getTypeChecker().isSubtypeOf(returnType, receiverType)) {
                                     context.trace.getErrorHandler().genericError(operationSign.getNode(), name + " must return " + receiverType + " but returns " + returnType);
                                 }
+                                else {
+                                    context.trace.recordVariableReassignment(expression);
+                                }
                                 // TODO : Maybe returnType?
                                 result = receiverType;
                             }

idea/tests/org/jetbrains/jet/JetTestUtils.java

@@ -54,7 +54,7 @@ public class JetTestUtils {
         }
 
         @Override
-        public void recordVariableReassignment(@NotNull JetBinaryExpression expression) {
+        public void recordVariableReassignment(@NotNull JetExpression expression) {
 
         }
 
@@ -191,7 +191,7 @@ public class JetTestUtils {
                 }
 
                 @Override
-                public boolean isVariableReassignment(JetBinaryExpression expression) {
+                public boolean isVariableReassignment(JetExpression expression) {
                     throw new UnsupportedOperationException(); // TODO
                 }