Fix danmar#7459 False positive (inconclusive): function can be static (danmar#6719)

Author: chrchr-github

lib/checkclass.cpp

@@ -2111,6 +2111,8 @@ void CheckClass::checkConst()
             // don't warn for friend/static/virtual functions
             if (func.isFriend() || func.isStatic() || func.hasVirtualSpecifier())
                 continue;
+            if (func.functionPointerUsage)
+                continue;
 
             // don't suggest const when returning non-const pointer/reference, but still suggest static
             auto isPointerOrReference = [this](const Token* start, const Token* end) -> bool {

test/testclass.cpp

@@ -185,6 +185,7 @@ class TestClass : public TestFixture {
         TEST_CASE(const91);
         TEST_CASE(const92);
         TEST_CASE(const93);
+        TEST_CASE(const94);
 
         TEST_CASE(const_handleDefaultParameters);
         TEST_CASE(const_passThisToMemberOfOtherClass);
@@ -6691,6 +6692,19 @@ class TestClass : public TestFixture {
                       errout_str());
     }
 
+    void const94() { // #7459
+        checkConst("class A {\n"
+                   "public:\n"
+                   "    A() : tickFunction(&A::nop) {}\n"
+                   "    void tick() { (this->*tickFunction)(); }\n"
+                   "private:\n"
+                   "    typedef void (A::* Fn)();\n"
+                   "    Fn tickFunction;\n"
+                   "    void nop() {}\n"
+                   "};\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void const_handleDefaultParameters() {
         checkConst("struct Foo {\n"
                    "    void foo1(int i, int j = 0) {\n"