Initial check for recommending algorithms (#1352)

Add initial check for loop algorithms

.travis_suppressions

@@ -5,6 +5,7 @@ nullPointer:lib/checkother.cpp
 nullPointer:build/checkother.cpp
 missingOverride
 noValidConfiguration
+useStlAlgorithm
 
 *:gui/test/*
 *:test/test.cxx

lib/checkstl.cpp

@@ -1746,3 +1746,343 @@ void CheckStl::readingEmptyStlContainerError(const Token *tok, const ValueFlow::
 
     reportError(errorPath, value ? (value->errorSeverity() ? Severity::error : Severity::warning) : Severity::style, "reademptycontainer", "$symbol:" + varname +"\n" + errmsg, CWE398, !value);
 }
+
+void CheckStl::useStlAlgorithmError(const Token *tok, const std::string &algoName)
+{
+    reportError(tok, Severity::style, "useStlAlgorithm",
+                "Consider using " + algoName + " algorithm instead of a raw loop.", CWE398, false);
+}
+
+static bool isEarlyExit(const Token *start)
+{
+    if (start->str() != "{")
+        return false;
+    const Token *endToken = start->link();
+    const Token *tok = Token::findmatch(start, "return|throw|break", endToken);
+    if (!tok)
+        return false;
+    const Token *endStatement = Token::findsimplematch(tok, "; }", endToken);
+    if (!endStatement)
+        return false;
+    if (endStatement->next() != endToken)
+        return false;
+    return true;
+}
+
+static const Token *singleStatement(const Token *start)
+{
+    if (start->str() != "{")
+        return nullptr;
+    const Token *endToken = start->link();
+    const Token *endStatement = Token::findsimplematch(start->next(), ";");
+    if (!Token::simpleMatch(endStatement, "; }"))
+        return nullptr;
+    if (endStatement->next() != endToken)
+        return nullptr;
+    return endStatement;
+}
+
+static const Token *singleAssignInScope(const Token *start, unsigned int varid, bool &input)
+{
+    const Token *endStatement = singleStatement(start);
+    if (!endStatement)
+        return nullptr;
+    if (!Token::Match(start->next(), "%var% %assign%"))
+        return nullptr;
+    const Token *assignTok = start->tokAt(2);
+    if (isVariableChanged(assignTok->next(), endStatement, assignTok->astOperand1()->varId(), false, nullptr, true))
+        return nullptr;
+    if (isVariableChanged(assignTok->next(), endStatement, varid, false, nullptr, true))
+        return nullptr;
+    input = Token::findmatch(assignTok->next(), "%varid%", endStatement, varid);
+    return assignTok;
+}
+
+static const Token *singleMemberCallInScope(const Token *start, unsigned int varid, bool &input)
+{
+    if (start->str() != "{")
+        return nullptr;
+    const Token *endToken = start->link();
+    if (!Token::Match(start->next(), "%var% . %name% ("))
+        return nullptr;
+    if (!Token::simpleMatch(start->linkAt(4), ") ; }"))
+        return nullptr;
+    const Token *endStatement = start->linkAt(4)->next();
+    if (endStatement->next() != endToken)
+        return nullptr;
+
+    const Token *dotTok = start->tokAt(2);
+    if (!Token::findmatch(dotTok->tokAt(2), "%varid%", endStatement, varid))
+        return nullptr;
+    input = Token::Match(start->next(), "%var% . %name% ( %varid% )", varid);
+    if (isVariableChanged(dotTok->next(), endStatement, dotTok->astOperand1()->varId(), false, nullptr, true))
+        return nullptr;
+    return dotTok;
+}
+
+static const Token *singleIncrementInScope(const Token *start, unsigned int varid, bool &input)
+{
+    if (start->str() != "{")
+        return nullptr;
+    const Token *varTok = nullptr;
+    if (Token::Match(start->next(), "++ %var% ; }"))
+        varTok = start->tokAt(2);
+    else if (Token::Match(start->next(), "%var% ++ ; }"))
+        varTok = start->tokAt(1);
+    if (!varTok)
+        return nullptr;
+    input = varTok->varId() == varid;
+    return varTok;
+}
+
+static const Token *singleConditionalInScope(const Token *start, unsigned int varid)
+{
+    if (start->str() != "{")
+        return nullptr;
+    const Token *endToken = start->link();
+    if (!Token::simpleMatch(start->next(), "if ("))
+        return nullptr;
+    if (!Token::simpleMatch(start->linkAt(2), ") {"))
+        return nullptr;
+    const Token *bodyTok = start->linkAt(2)->next();
+    const Token *endBodyTok = bodyTok->link();
+    if (!Token::simpleMatch(endBodyTok, "} }"))
+        return nullptr;
+    if (endBodyTok->next() != endToken)
+        return nullptr;
+    if (!Token::findmatch(start, "%varid%", bodyTok, varid))
+        return nullptr;
+    if (isVariableChanged(start, bodyTok, varid, false, nullptr, true))
+        return nullptr;
+    return bodyTok;
+}
+
+static bool addByOne(const Token *tok, unsigned int varid)
+{
+    if (Token::Match(tok, "+= %any% ;") &&
+        tok->tokAt(1)->hasKnownIntValue() &&
+        tok->tokAt(1)->getValue(1)) {
+        return true;
+    }
+    if (Token::Match(tok, "= %varid% + %any% ;", varid) &&
+        tok->tokAt(3)->hasKnownIntValue() &&
+        tok->tokAt(3)->getValue(1)) {
+        return true;
+    }
+    return false;
+}
+
+static bool accumulateBoolLiteral(const Token *tok, unsigned int varid)
+{
+    // TODO: Missing %oreq%
+    if (Token::Match(tok, "=|&= %bool% ;") &&
+        tok->tokAt(1)->hasKnownIntValue()) {
+        return true;
+    }
+    if (Token::Match(tok, "= %varid% %oror%|%or%|&&|& %bool% ;", varid) &&
+        tok->tokAt(3)->hasKnownIntValue()) {
+        return true;
+    }
+    return false;
+}
+
+static bool accumulateBool(const Token *tok, unsigned int varid)
+{
+    // TODO: Missing %oreq%
+    if (Token::simpleMatch(tok, "&=")) {
+        return true;
+    }
+    if (Token::Match(tok, "= %varid% %oror%|%or%|&&|&", varid)) {
+        return true;
+    }
+    return false;
+}
+
+static bool hasVarIds(const Token *tok, unsigned int var1, unsigned int var2)
+{
+    if (tok->astOperand1()->varId() == tok->astOperand2()->varId())
+        return false;
+    if (tok->astOperand1()->varId() == var1 || tok->astOperand1()->varId() == var2) {
+        if (tok->astOperand2()->varId() == var1 || tok->astOperand2()->varId() == var2) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static std::string flipMinMax(const std::string &algo)
+{
+    if (algo == "std::max_element")
+        return "std::min_element";
+    if (algo == "std::min_element")
+        return "std::max_element";
+    return algo;
+}
+
+static std::string minmaxCompare(const Token *condTok, unsigned int loopVar, unsigned int assignVar, bool invert = false)
+{
+    if (!Token::Match(condTok, "<|<=|>=|>"))
+        return "std::accumulate";
+    if (!hasVarIds(condTok, loopVar, assignVar))
+        return "std::accumulate";
+    std::string algo = "std::max_element";
+    if (Token::Match(condTok, "<|<="))
+        algo = "std::min_element";
+    if (condTok->astOperand1()->varId() == assignVar)
+        algo = flipMinMax(algo);
+    if (invert)
+        algo = flipMinMax(algo);
+    return algo;
+}
+
+void CheckStl::useStlAlgorithm()
+{
+    if (!mSettings->isEnabled(Settings::STYLE))
+        return;
+    for (const Scope *function : mTokenizer->getSymbolDatabase()->functionScopes) {
+        for (const Token *tok = function->bodyStart; tok != function->bodyEnd; tok = tok->next()) {
+            // Parse range-based for loop
+            if (!Token::simpleMatch(tok, "for ("))
+                continue;
+            if (!Token::simpleMatch(tok->next()->link(), ") {"))
+                continue;
+            const Token *bodyTok = tok->next()->link()->next();
+            const Token *splitTok = tok->next()->astOperand2();
+            if (!Token::simpleMatch(splitTok, ":"))
+                continue;
+            const Token *loopVar = splitTok->previous();
+            if (!Token::Match(loopVar, "%var%"))
+                continue;
+
+            // Check for single assignment
+            bool useLoopVarInAssign;
+            const Token *assignTok = singleAssignInScope(bodyTok, loopVar->varId(), useLoopVarInAssign);
+            if (assignTok) {
+                unsigned int assignVarId = assignTok->astOperand1()->varId();
+                std::string algo;
+                if (assignVarId == loopVar->varId()) {
+                    if (useLoopVarInAssign)
+                        algo = "std::transform";
+                    else if (Token::Match(assignTok->next(), "%var%|%bool%|%num%|%char% ;"))
+                        algo = "std::fill";
+                    else if (Token::Match(assignTok->next(), "%name% ( )"))
+                        algo = "std::generate";
+                    else
+                        algo = "std::fill or std::generate";
+                } else {
+                    if (addByOne(assignTok, assignVarId))
+                        algo = "std::distance";
+                    else if (accumulateBool(assignTok, assignVarId))
+                        algo = "std::any_of, std::all_of, std::none_of, or std::accumulate";
+                    else if (Token::Match(assignTok, "= %var% <|<=|>=|> %var% ? %var% : %var%") && hasVarIds(assignTok->tokAt(6), loopVar->varId(), assignVarId))
+                        algo = minmaxCompare(assignTok->tokAt(2), loopVar->varId(), assignVarId, assignTok->tokAt(5)->varId() == assignVarId);
+                    else
+                        algo = "std::accumulate";
+                }
+                useStlAlgorithmError(assignTok, algo);
+                continue;
+            }
+            // Check for container calls
+            bool useLoopVarInMemCall;
+            const Token *memberAccessTok = singleMemberCallInScope(bodyTok, loopVar->varId(), useLoopVarInMemCall);
+            if (memberAccessTok) {
+                const Token *memberCallTok = memberAccessTok->astOperand2();
+                unsigned int contVarId = memberAccessTok->astOperand1()->varId();
+                if (contVarId == loopVar->varId())
+                    continue;
+                if (memberCallTok->str() == "push_back" ||
+                    memberCallTok->str() == "push_front" ||
+                    memberCallTok->str() == "emplace_back") {
+                    std::string algo;
+                    if (useLoopVarInMemCall)
+                        algo = "std::copy";
+                    else
+                        algo = "std::transform";
+                    useStlAlgorithmError(assignTok, algo);
+                }
+                continue;
+            }
+
+            // Check for increment in loop
+            bool useLoopVarInIncrement;
+            const Token *incrementTok = singleIncrementInScope(bodyTok, loopVar->varId(), useLoopVarInIncrement);
+            if (incrementTok) {
+                std::string algo;
+                if (useLoopVarInIncrement)
+                    algo = "std::transform";
+                else
+                    algo = "std::distance";
+                useStlAlgorithmError(incrementTok, algo);
+                continue;
+            }
+
+            // Check for conditionals
+            const Token *condBodyTok = singleConditionalInScope(bodyTok, loopVar->varId());
+            if (condBodyTok) {
+                const Token *beginCondTok = condBodyTok->previous()->link();
+                // Check for single assign
+                assignTok = singleAssignInScope(condBodyTok, loopVar->varId(), useLoopVarInAssign);
+                if (assignTok) {
+                    unsigned int assignVarId = assignTok->astOperand1()->varId();
+                    std::string algo;
+                    if (assignVarId == loopVar->varId()) {
+                        if (useLoopVarInAssign)
+                            algo = "std::transform";
+                        else
+                            algo = "std::replace_if";
+                    } else {
+                        if (addByOne(assignTok, assignVarId))
+                            algo = "std::count_if";
+                        else if (accumulateBoolLiteral(assignTok, assignVarId))
+                            algo = "std::any_of, std::all_of, std::none_of, or std::accumulate";
+                        else
+                            algo = "std::accumulate";
+                    }
+                    useStlAlgorithmError(assignTok, algo);
+                    continue;
+                }
+
+                // Check for container call
+                memberAccessTok = singleMemberCallInScope(condBodyTok, loopVar->varId(), useLoopVarInMemCall);
+                if (memberAccessTok) {
+                    const Token *memberCallTok = memberAccessTok->astOperand2();
+                    unsigned int contVarId = memberAccessTok->astOperand1()->varId();
+                    if (contVarId == loopVar->varId())
+                        continue;
+                    if (memberCallTok->str() == "push_back" ||
+                        memberCallTok->str() == "push_front" ||
+                        memberCallTok->str() == "emplace_back") {
+                        if (useLoopVarInMemCall)
+                            useStlAlgorithmError(memberAccessTok, "std::copy_if");
+                        // There is no transform_if to suggest
+                    }
+                    continue;
+                }
+
+                // Check for increment in loop
+                incrementTok = singleIncrementInScope(condBodyTok, loopVar->varId(), useLoopVarInIncrement);
+                if (incrementTok) {
+                    std::string algo;
+                    if (useLoopVarInIncrement)
+                        algo = "std::transform";
+                    else
+                        algo = "std::count_if";
+                    useStlAlgorithmError(incrementTok, algo);
+                    continue;
+                }
+
+                // Check early return
+                if (isEarlyExit(condBodyTok)) {
+                    const Token *loopVar2 = Token::findmatch(condBodyTok, "%varid%", condBodyTok->link(), loopVar->varId());
+                    std::string algo;
+                    if (loopVar2)
+                        algo = "std::find_if";
+                    else
+                        algo = "std::any_of";
+                    useStlAlgorithmError(condBodyTok, algo);
+                    continue;
+                }
+            }
+        }
+    }
+}

lib/checkstl.h

@@ -88,6 +88,7 @@ public:
         checkStl.size();
         checkStl.redundantCondition();
         checkStl.missingComparison();
+        checkStl.useStlAlgorithm();
     }
 
     /** Accessing container out of bounds using ValueFlow */
@@ -179,6 +180,10 @@ public:
 
     /** @brief Reading from empty stl container (using valueflow) */
     void readingEmptyStlContainer2();
+
+    /** @brief Look for loops that can replaced with std algorithms */
+    void useStlAlgorithm();
+
   private:
     void missingComparisonError(const Token* incrementToken1, const Token* incrementToken2);
     void string_c_strThrowError(const Token* tok);
@@ -216,6 +221,8 @@ private:
 
     void readingEmptyStlContainerError(const Token* tok, const ValueFlow::Value *value=nullptr);
 
+    void useStlAlgorithmError(const Token *tok, const std::string &algoName);
+
     void getErrorMessages(ErrorLogger* errorLogger, const Settings* settings) const override {
         CheckStl c(nullptr, settings, errorLogger);
         c.outOfBoundsError(nullptr, nullptr, nullptr);
@@ -250,6 +257,7 @@ private:
         c.uselessCallsRemoveError(nullptr, "remove");
         c.dereferenceInvalidIteratorError(nullptr, "i");
         c.readingEmptyStlContainerError(nullptr);
+        c.useStlAlgorithmError(nullptr, "");
     }
 
     static std::string myName() {
@@ -271,7 +279,8 @@ private:
                "- using auto pointer (auto_ptr)\n"
                "- useless calls of string and STL functions\n"
                "- dereferencing an invalid iterator\n"
-               "- reading from empty STL container\n";
+               "- reading from empty STL container\n"
+               "- consider using an STL algorithm instead of raw loop\n";
     }
 };
 /// @}

test/teststl.cpp

@@ -144,6 +144,13 @@ private:
         TEST_CASE(dereferenceInvalidIterator);
         TEST_CASE(dereferenceInvalidIterator2); // #6572
         TEST_CASE(dereference_auto);
+
+        TEST_CASE(loopAlgoElementAssign);
+        TEST_CASE(loopAlgoAccumulateAssign);
+        TEST_CASE(loopAlgoContainerInsert);
+        TEST_CASE(loopAlgoIncrement);
+        TEST_CASE(loopAlgoConditional);
+        TEST_CASE(loopAlgoMinMax);
     }
 
     void check(const char code[], const bool inconclusive=false, const Standards::cppstd_t cppstandard=Standards::CPP11) {
@@ -3156,6 +3163,514 @@ private:
               "}\n");
         ASSERT_EQUALS("[test.cpp:18]: (error, inconclusive) Invalid iterator 'it' used.\n", errout.str());
     }
+
+    void loopAlgoElementAssign()
+    {
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x = 1;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::fill algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x = x + 1;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo(int a, int b) {\n"
+              "    for(int& x:v)\n"
+              "        x = a + b;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::fill or std::generate algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x += 1;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x = f();\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::generate algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        f();\n"
+              "        x = 1;\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        x = 1;\n"
+              "        f();\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        // There should probably be a message for unconditional break
+        check("void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        x = 1;\n"
+              "        break;\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x = ++x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+    }
+
+    void loopAlgoAccumulateAssign()
+    {
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n += x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = n + x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n += 1;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::distance algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = n + 1;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::distance algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool f(int);\n"
+              "void foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v)\n"
+              "        b &= f(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool f(int);\n"
+              "void foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v)\n"
+              "        b |= f(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool f(int);\n"
+              "void foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v)\n"
+              "        b = b && f(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool f(int);\n"
+              "void foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v)\n"
+              "        b = b || f(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int& x:v)\n"
+              "        n = ++x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+    }
+
+    void loopAlgoContainerInsert()
+    {
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_back(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::copy algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_back(f(x));\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_back(x + 1);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_front(x);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::copy algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_front(f(x));\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_front(x + 1);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("(style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_back(v);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        check("void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v)\n"
+              "        c.push_back(0);\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+    }
+
+    void loopAlgoIncrement()
+    {
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n++;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::distance algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        ++n;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::distance algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        x++;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    for(int& x:v)\n"
+              "        ++x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:3]: (style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+    }
+
+    void loopAlgoConditional()
+    {
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            x = 1; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::replace_if algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            n += x; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            n += 1; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::count_if algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            n++; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::count_if algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            x = x + 1; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::transform algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            c.push_back(x); \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::copy_if algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            return false; \n"
+              "        }\n"
+              "    }\n"
+              "    return true;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::any_of algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            break; \n"
+              "        }\n"
+              "    }\n"
+              "    return true;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::any_of algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void f();\n"
+              "void foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            f(); \n"
+              "            break; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::any_of algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "void f(int x);\n"
+              "void foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            f(x); \n"
+              "            break; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:5]: (style) Consider using std::find_if algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            b = true;\n"
+              "        }\n"
+              "    }\n"
+              "    if(b) {}\n"
+              "    return true;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            b |= true;\n"
+              "        }\n"
+              "    }\n"
+              "    return true;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    bool b = false;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            b &= true;\n"
+              "        }\n"
+              "    }\n"
+              "    return true;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:6]: (style) Consider using std::any_of, std::all_of, std::none_of, or std::accumulate algorithm instead of a raw loop.\n", errout.str());
+
+        check("bool pred(int x);\n"
+              "bool foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            return false; \n"
+              "        }\n"
+              "        return true;\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        // There is no transform_if
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    std::vector<int> c;\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            c.push_back(x + 1); \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        check("bool pred(int x);\n"
+              "void foo() {\n"
+              "    for(int& x:v) {\n"
+              "        x++;\n"
+              "        if (pred(x)) {\n"
+              "            x = 1; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+
+        check("bool pred(int x);\n"
+              "void f();\n"
+              "void foo() {\n"
+              "    for(int x:v) {\n"
+              "        if (pred(x)) {\n"
+              "            if(x) { return; }\n"
+              "            break; \n"
+              "        }\n"
+              "    }\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("", errout.str());
+    }
+
+    void loopAlgoMinMax()
+    {
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = x > n ? x : n;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::max_element algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = x < n ? x : n;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::min_element algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = x > n ? n : x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::min_element algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo() {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = x < n ? n : x;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::max_element algorithm instead of a raw loop.\n", errout.str());
+
+        check("void foo(int m) {\n"
+              "    int n = 0;\n"
+              "    for(int x:v)\n"
+              "        n = x > m ? x : n;\n"
+              "}\n",
+              true);
+        ASSERT_EQUALS("[test.cpp:4]: (style) Consider using std::accumulate algorithm instead of a raw loop.\n", errout.str());
+    }
 };
 
 REGISTER_TEST(TestStl)