Fixed #2321 (false positive: (performance) Prefer prefix ++/-- operators for non-primitive types.)

lib/checkpostfixoperator.cpp

@@ -74,6 +74,9 @@ void CheckPostfixOperator::postfixOperator()
         if (result && tok->previous()->varId())
         {
             const Token *decltok = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->previous()->varId());
+            if (!Token::Match(decltok->tokAt(-1), "%type%"))
+                continue;
+
             if (decltok && Token::Match(decltok->previous(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator"))
             {
                 // the variable is an iterator

test/testpostfixoperator.cpp

@@ -69,6 +69,7 @@ private:
         TEST_CASE(testvolatile);
         TEST_CASE(testiterator);
         TEST_CASE(test2168);
+        TEST_CASE(pointer);   // #2321 - postincrement of pointer is OK
     }
 
     void testsimple()
@@ -372,6 +373,14 @@ private:
               "int main(){}\n");
         ASSERT_EQUALS("", errout.str());
     }
+
+    void pointer()
+    {
+        check("static struct class * ab;\n"
+              "int * p;\n"
+              "p++;\n");
+        ASSERT_EQUALS("", errout.str());
+    }
 };
 
 REGISTER_TEST(TestPostfixOperator)