Partial fix for #11469 FP mismatchingContainerExpression warning (#5674)

Author: chrchr-github

lib/checkstl.cpp

@@ -747,8 +747,8 @@ bool CheckStl::checkIteratorPair(const Token* tok1, const Token* tok2)
     }
 
     if (Token::Match(tok1->astParent(), "%comp%|-")) {
-        if (astIsIntegral(tok1, false) || astIsIntegral(tok2, false) || astIsFloat(tok1, false) ||
-            astIsFloat(tok2, false))
+        if (astIsIntegral(tok1, true) || astIsIntegral(tok2, true) ||
+            astIsFloat(tok1, true) || astIsFloat(tok2, true))
             return false;
     }
     const Token* iter1 = getIteratorExpression(tok1);

test/teststl.cpp

@@ -1989,6 +1989,23 @@ class TestStl : public TestFixture {
               "    }\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("bool f(const std::vector<int>& a, const std::vector<int>& b) {\n" // #11469
+              "    return (a.begin() - a.end()) == (b.begin() - b.end());\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        check("struct S {\n"
+              "    const std::vector<int>* vec() const { return &v; }\n"
+              "    const std::vector<int> v;\n"
+              "};\n"
+              "void f(const S& a, const S& b) {\n"
+              "    if (a.vec()->begin() - a.vec()->end() != b.vec()->begin() - b.vec()->end()) {}\n"
+              "}\n");
+        TODO_ASSERT_EQUALS("",
+                           "[test.cpp:6]: (warning) Iterators to containers from different expressions 'a.vec()' and 'a.vec()' are used together.\n"
+                           "[test.cpp:6]: (warning) Iterators to containers from different expressions 'b.vec()' and 'b.vec()' are used together.\n",
+                           errout.str());
     }
 
     void iteratorSameExpression() {