From a0d8f44603c76f4a798afe40d5b7d6adc7b43aca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <danielm77@spray.se>
Date: Sat, 23 Jan 2010 22:36:04 +0100
Subject: [PATCH] CheckClass: The operator< etc member functions can often be
 const

---
 lib/checkclass.cpp | 17 +++++++++++------
 test/testclass.cpp | 11 +++++++++++
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index e6d79497e..784ccfc8d 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1406,7 +1406,7 @@ void CheckClass::checkConst()
 
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
     {
-        if (Token::Match(tok, "class %var% :|{"))
+        if (Token::Match(tok, "class|struct %var% :|{"))
         {
             // get class name..
             const std::string classname(tok->strAt(1));
@@ -1426,19 +1426,24 @@ void CheckClass::checkConst()
                     break;
 
                 // member function?
-                if (Token::Match(tok2, "[;}] %type% %var% ("))
+                if (Token::Match(tok2, "[;}] %type% %var% (") ||
+                    Token::Match(tok2, "[;}] %type% operator %any% ("))
                 {
+                    // goto function name..
+                    while (tok2->next()->str() != "(")
+                        tok2 = tok2->next();
+
                     // get function name
-                    const std::string functionName(tok2->strAt(2));
+                    const std::string functionName((tok2->isName() ? "" : "operator") + tok2->str());
                     if (functionName == classname)
                         continue;
 
                     // goto the ')'
-                    tok2 = tok2->tokAt(3)->link();
+                    tok2 = tok2->next()->link();
                     if (!tok2)
                         break;
 
-                    // is this function implemented inline?
+                    // is this a non-const function that is implemented inline?
                     if (Token::simpleMatch(tok2, ") {"))
                     {
                         // if the function doesn't have any assignment nor function call,
@@ -1466,7 +1471,7 @@ void CheckClass::checkConst()
                             }
 
                             // function call..
-                            else if (Token::Match(tok3, "%var% ("))
+                            else if (tok3->str() != "return" && Token::Match(tok3, "%var% ("))
                             {
                                 isconst = false;
                                 break;
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 0980335ec..425f96737 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -81,6 +81,7 @@ private:
 
         // can member function be made const
         TEST_CASE(const1);
+        TEST_CASE(const2);
     }
 
     // Check the operator Equal
@@ -1555,6 +1556,16 @@ private:
                    "};\n");
         ASSERT_EQUALS("", errout.str());
     }
+
+    // operator< can often be const
+    void const2()
+    {
+        checkConst("struct Fred {\n"
+                   "    int a;\n"
+                   "    bool operator<(const Fred &f) { return (a < f.a); }\n"
+                   "};\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) The function 'Fred::operator<' can be const\n", errout.str());
+    }
 };
 
 REGISTER_TEST(TestClass)