diff --git a/lib/checkbufferoverrun.cpp b/lib/checkbufferoverrun.cpp
index 8c6a6b774..595f49704 100644
--- a/lib/checkbufferoverrun.cpp
+++ b/lib/checkbufferoverrun.cpp
@@ -480,7 +480,7 @@ void CheckBufferOverrun::parse_for_body(const Token *tok2, const ArrayInfo &arra
                 const char action = tok2->strAt(3)[0];
 
                 // second operator
-                const std::string &second(tok2->tokAt(4)->str());
+                const std::string &second(tok2->strAt(4));
 
                 //printf("min_index: %s %c %s\n", min_counter_value.c_str(), action, second.c_str());
                 //printf("max_index: %s %c %s\n", max_counter_value.c_str(), action, second.c_str());
@@ -493,7 +493,7 @@ void CheckBufferOverrun::parse_for_body(const Token *tok2, const ArrayInfo &arra
                 const char action = tok2->strAt(3)[0];
 
                 // first operand
-                const std::string &first(tok2->tokAt(2)->str());
+                const std::string &first(tok2->strAt(2));
 
                 //printf("min_index: %s %c %s\n", first.c_str(), action, min_counter_value.c_str());
                 //printf("max_index: %s %c %s\n", first.c_str(), action, max_counter_value.c_str());
@@ -1233,9 +1233,9 @@ void CheckBufferOverrun::checkReadlinkBufferUsage(const Token* tok, const Token
     }
 
     if (!found_termination) {
-        bufferNotZeroTerminatedError(tok, tok->tokAt(4 + param_offset)->str(), funcname);
+        bufferNotZeroTerminatedError(tok, tok->strAt(4 + param_offset), funcname);
     } else if (n == total_size) {
-        possibleReadlinkBufferOverrunError(tok, funcname, tok->tokAt(4 + param_offset)->str());
+        possibleReadlinkBufferOverrunError(tok, funcname, tok->strAt(4 + param_offset));
     }
 }
 
@@ -1717,7 +1717,7 @@ void CheckBufferOverrun::checkBufferAllocatedWithStrlen()
                 bufferOverrunError(tok);
             } else if (Token::Match(tok, "sprintf ( %varid% , %str% , %var% )", dstVarId) &&
                        tok->tokAt(6)->varId() == srcVarId &&
-                       tok->tokAt(4)->str().find("%s") != std::string::npos) {
+                       tok->strAt(4).find("%s") != std::string::npos) {
                 bufferOverrunError(tok);
             }
 
@@ -1781,10 +1781,10 @@ void CheckBufferOverrun::checkInsecureCmdLineArgs()
                 Token::Match(tok, "strcpy|strcat ( %var% , %varid% [", varid)) {
                 cmdLineArgsError(tok);
             } else if (Token::Match(tok, "sprintf ( %var% , %str% , %varid% [", varid) &&
-                       tok->tokAt(4)->str().find("%s") != std::string::npos) {
+                       tok->strAt(4).find("%s") != std::string::npos) {
                 cmdLineArgsError(tok);
             } else if (Token::Match(tok, "sprintf ( %var% , %str% , * %varid%", varid) &&
-                       tok->tokAt(4)->str().find("%s") != std::string::npos) {
+                       tok->strAt(4).find("%s") != std::string::npos) {
                 cmdLineArgsError(tok);
             }
 
diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 38b4e0ad3..26ab9ec34 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -990,10 +990,10 @@ bool CheckClass::hasAssignSelf(const Function *func, const Token *rhs)
             if (tok1 && tok2) {
                 for (; tok1 && tok1 != tok2; tok1 = tok1->next()) {
                     if (Token::Match(tok1, "this ==|!= & %var%")) {
-                        if (tok1->tokAt(3)->str() == rhs->str())
+                        if (tok1->strAt(3) == rhs->str())
                             return true;
                     } else if (Token::Match(tok1, "& %var% ==|!= this")) {
-                        if (tok1->tokAt(1)->str() == rhs->str())
+                        if (tok1->strAt(1) == rhs->str())
                             return true;
                     }
                 }
diff --git a/lib/checkexceptionsafety.cpp b/lib/checkexceptionsafety.cpp
index c6212f0f2..a9037726e 100644
--- a/lib/checkexceptionsafety.cpp
+++ b/lib/checkexceptionsafety.cpp
@@ -173,7 +173,7 @@ void CheckExceptionSafety::checkRethrowCopy()
 
         const Token* rethrowTok = Token::findmatch(startBlockTok, "throw %varid%", endBlockTok, varid);
         if (rethrowTok) {
-            rethrowCopyError(rethrowTok, startBlockTok->tokAt(-2)->str());
+            rethrowCopyError(rethrowTok, startBlockTok->strAt(-2));
         }
 
         tok = Token::findmatch(endBlockTok->next(), catchPattern);
diff --git a/lib/checkmemoryleak.cpp b/lib/checkmemoryleak.cpp
index 8c42175e9..2aafbbc5d 100644
--- a/lib/checkmemoryleak.cpp
+++ b/lib/checkmemoryleak.cpp
@@ -2291,7 +2291,7 @@ void CheckMemoryLeakInFunction::checkReallocUsage()
                         Token::Match(tokEndBrace->tokAt(-2)->link()->tokAt(-2), "{|}|; %var% ("))
                         continue;
                 }
-                memleakUponReallocFailureError(tok->tokAt(1), tok->tokAt(1)->str());
+                memleakUponReallocFailureError(tok->tokAt(1), tok->strAt(1));
             }
         }
     }
@@ -2361,12 +2361,12 @@ void CheckMemoryLeakInFunction::parseFunctionScope(const Token *tok, const Token
             sz = 1;
 
         if (Token::Match(tok, "[{};] %type% * const| %var% [;=]")) {
-            const Token *vartok = tok->tokAt(tok->tokAt(3)->str() != "const" ? 3 : 4);
+            const Token *vartok = tok->tokAt(tok->strAt(3) != "const" ? 3 : 4);
             checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz);
         }
 
         else if (Token::Match(tok, "[{};] %type% %type% * const| %var% [;=]")) {
-            const Token *vartok = tok->tokAt(tok->tokAt(4)->str() != "const" ? 4 : 5);
+            const Token *vartok = tok->tokAt(tok->strAt(4) != "const" ? 4 : 5);
             checkScope(tok->next(), vartok->str(), vartok->varId(), classmember, sz);
         }
 
diff --git a/lib/checknullpointer.cpp b/lib/checknullpointer.cpp
index a167de331..7069c15dc 100644
--- a/lib/checknullpointer.cpp
+++ b/lib/checknullpointer.cpp
@@ -720,7 +720,7 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
                 const Token *endbody = Token::simpleMatch(endpar, ") {") ? endpar->next()->link() : 0;
                 if (endbody &&
                     Token::Match(endbody->tokAt(-3), "[;{}] %var% ;") &&
-                    isUpper(endbody->tokAt(-2)->str()))
+                    isUpper(endbody->strAt(-2)))
                     continue;
             }
 
diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index b219833ec..ea098ef3b 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -291,14 +291,14 @@ void CheckOther::warningOldStylePointerCast()
             continue;
 
         unsigned char addToIndex = 0;
-        if (tok->tokAt(1)->str() == "const")
+        if (tok->strAt(1) == "const")
             addToIndex = 1;
 
-        if (tok->tokAt(4 + addToIndex)->str() == "const")
+        if (tok->strAt(4 + addToIndex) == "const")
             continue;
 
         // Is "type" a class?
-        const std::string pattern("class " + tok->tokAt(1 + addToIndex)->str());
+        const std::string pattern("class " + tok->strAt(1 + addToIndex));
         if (!Token::findmatch(_tokenizer->tokens(), pattern.c_str()))
             continue;
 
@@ -364,7 +364,7 @@ void CheckOther::checkSizeofForArrayParameter()
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::Match(tok, "sizeof ( %var% )") || Token::Match(tok, "sizeof %var%")) {
             unsigned short tokIdx = 1;
-            if (tok->tokAt(tokIdx)->str() == "(") {
+            if (tok->strAt(tokIdx) == "(") {
                 ++tokIdx;
             }
             if (tok->tokAt(tokIdx)->varId() > 0) {
@@ -433,7 +433,7 @@ void CheckOther::checkSizeofForStrncmpSize()
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::Match(tok, pattern1) || Token::Match(tok, pattern2)) {
             unsigned short tokIdx = 7;
-            if (tok->tokAt(tokIdx)->str() == "(")
+            if (tok->strAt(tokIdx) == "(")
                 ++tokIdx;
             const Token *tokVar = tok->tokAt(tokIdx);
             if (tokVar->varId() > 0) {
@@ -891,7 +891,7 @@ void CheckOther::checkIncorrectLogicOperator()
                     continue;
                 }
                 varFirst1 = true;
-                firstConstant = term1Tok->tokAt(2)->str();
+                firstConstant = term1Tok->strAt(2);
             } else if (Token::Match(term1Tok, "%num% %any% %var%")) {
                 varTok = term1Tok->tokAt(2);
                 varId = varTok->varId();
@@ -916,7 +916,7 @@ void CheckOther::checkIncorrectLogicOperator()
                     continue;
                 }
                 varFirst2 = true;
-                secondConstant = term2Tok->tokAt(2)->str();
+                secondConstant = term2Tok->strAt(2);
                 variableTested = varId;
             } else if (Token::Match(term2Tok, "%num% %any% %var%")) {
                 const unsigned int varId2 = term1Tok->tokAt(2)->varId();
@@ -1331,13 +1331,13 @@ void CheckOther::checkComparisonOfBoolWithInt()
     std::map<unsigned int, bool> boolvars; // Contains all declarated standard type variables and indicates whether its a bool or not.
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::Match(tok, "[{};(,] %type% %var% [;=,)]") && tok->tokAt(1)->isStandardType()) { // Declaration of standard type variable
-            boolvars[tok->tokAt(2)->varId()] = (tok->tokAt(1)->str() == "bool");
+            boolvars[tok->tokAt(2)->varId()] = (tok->strAt(1) == "bool");
         } else if (Token::Match(tok, "%var% >|>=|==|!=|<=|< %num%")) { // Comparing variable with number
             const Token *varTok = tok;
             const Token *numTok = tok->tokAt(2);
             std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
             if (iVar != boolvars.end() && iVar->second && // Variable has to be a boolean
-                ((tok->tokAt(1)->str() != "==" && tok->tokAt(1)->str() != "!=") ||
+                ((tok->strAt(1) != "==" && tok->strAt(1) != "!=") ||
                  ((MathLib::toLongNumber(numTok->str()) != 0) && (!_tokenizer->code_is_c() || MathLib::toLongNumber(numTok->str()) != 1)))) { // == 0 and != 0 are allowed, for C also == 1 and != 1
                 comparisonOfBoolWithIntError(varTok, numTok->str());
             }
@@ -1346,7 +1346,7 @@ void CheckOther::checkComparisonOfBoolWithInt()
             const Token *numTok = tok;
             std::map<unsigned int, bool>::const_iterator iVar = boolvars.find(varTok->varId());
             if (iVar != boolvars.end() && iVar->second && // Variable has to be a boolean
-                ((tok->tokAt(1)->str() != "==" && tok->tokAt(1)->str() != "!=") ||
+                ((tok->strAt(1) != "==" && tok->strAt(1) != "!=") ||
                  ((MathLib::toLongNumber(numTok->str()) != 0) && (!_tokenizer->code_is_c() || MathLib::toLongNumber(numTok->str()) != 1)))) { // == 0 and != 0 are allowed, for C also == 1 and != 1
                 comparisonOfBoolWithIntError(varTok, numTok->str());
             }
@@ -1963,8 +1963,8 @@ void CheckOther::checkZeroDivision()
             MathLib::toLongNumber(tok->next()->str()) == 0L) {
             zerodivError(tok);
         } else if (Token::Match(tok, "div|ldiv|lldiv|imaxdiv ( %num% , %num% )") &&
-                   MathLib::isInt(tok->tokAt(4)->str()) &&
-                   MathLib::toLongNumber(tok->tokAt(4)->str()) == 0L) {
+                   MathLib::isInt(tok->strAt(4)) &&
+                   MathLib::toLongNumber(tok->strAt(4)) == 0L) {
             zerodivError(tok);
         }
     }
@@ -1981,16 +1981,16 @@ void CheckOther::checkMathFunctions()
 {
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (tok->varId() == 0 && Token::Match(tok, "log|log10 ( %num% )")) {
-            bool isNegative = MathLib::isNegative(tok->tokAt(2)->str());
-            bool isInt = MathLib::isInt(tok->tokAt(2)->str());
-            bool isFloat = MathLib::isFloat(tok->tokAt(2)->str());
-            if (isNegative && isInt && MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0) {
+            bool isNegative = MathLib::isNegative(tok->strAt(2));
+            bool isInt = MathLib::isInt(tok->strAt(2));
+            bool isFloat = MathLib::isFloat(tok->strAt(2));
+            if (isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
                 mathfunctionCallError(tok); // case log(-2)
-            } else if (isNegative && isFloat && MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.) {
+            } else if (isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
                 mathfunctionCallError(tok); // case log(-2.0)
-            } else if (!isNegative && isFloat && MathLib::toDoubleNumber(tok->tokAt(2)->str()) <= 0.) {
+            } else if (!isNegative && isFloat && MathLib::toDoubleNumber(tok->strAt(2)) <= 0.) {
                 mathfunctionCallError(tok); // case log(0.0)
-            } else if (!isNegative && isInt && MathLib::toLongNumber(tok->tokAt(2)->str()) <= 0) {
+            } else if (!isNegative && isInt && MathLib::toLongNumber(tok->strAt(2)) <= 0) {
                 mathfunctionCallError(tok); // case log(0)
             }
         }
@@ -1998,33 +1998,33 @@ void CheckOther::checkMathFunctions()
         // acos( x ), asin( x )  where x is defined for intervall [-1,+1], but not beyound
         else if (tok->varId() == 0 &&
                  Token::Match(tok, "acos|asin ( %num% )") &&
-                 std::fabs(MathLib::toDoubleNumber(tok->tokAt(2)->str())) > 1.0) {
+                 std::fabs(MathLib::toDoubleNumber(tok->strAt(2))) > 1.0) {
             mathfunctionCallError(tok);
         }
         // sqrt( x ): if x is negative the result is undefined
         else if (tok->varId() == 0 &&
                  Token::Match(tok, "sqrt|sqrtf|sqrtl ( %num% )") &&
-                 MathLib::isNegative(tok->tokAt(2)->str())) {
+                 MathLib::isNegative(tok->strAt(2))) {
             mathfunctionCallError(tok);
         }
         // atan2 ( x , y): x and y can not be zero, because this is mathematically not defined
         else if (tok->varId() == 0 &&
                  Token::Match(tok, "atan2 ( %num% , %num% )") &&
-                 MathLib::isNullValue(tok->tokAt(2)->str()) &&
-                 MathLib::isNullValue(tok->tokAt(4)->str())) {
+                 MathLib::isNullValue(tok->strAt(2)) &&
+                 MathLib::isNullValue(tok->strAt(4))) {
             mathfunctionCallError(tok, 2);
         }
         // fmod ( x , y) If y is zero, then either a range error will occur or the function will return zero (implementation-defined).
         else if (tok->varId() == 0 &&
                  Token::Match(tok, "fmod ( %num% , %num% )") &&
-                 MathLib::isNullValue(tok->tokAt(4)->str())) {
+                 MathLib::isNullValue(tok->strAt(4))) {
             mathfunctionCallError(tok, 2);
         }
         // pow ( x , y) If x is zero, and y is negative --> division by zero
         else if (tok->varId() == 0 &&
                  Token::Match(tok, "pow ( %num% , %num% )") &&
-                 MathLib::isNullValue(tok->tokAt(2)->str())  &&
-                 MathLib::isNegative(tok->tokAt(4)->str())) {
+                 MathLib::isNullValue(tok->strAt(2))  &&
+                 MathLib::isNegative(tok->strAt(4))) {
             mathfunctionCallError(tok, 2);
         }
 
@@ -2035,9 +2035,9 @@ void CheckOther::mathfunctionCallError(const Token *tok, const unsigned int numP
 {
     if (tok) {
         if (numParam == 1)
-            reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " to " + tok->str() + "() leads to undefined result");
+            reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->strAt(2) + " to " + tok->str() + "() leads to undefined result");
         else if (numParam == 2)
-            reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->tokAt(2)->str() + " and " + tok->tokAt(4)->str() + " to " + tok->str() + "() leads to undefined result");
+            reportError(tok, Severity::error, "wrongmathcall", "Passing value " + tok->strAt(2) + " and " + tok->strAt(4) + " to " + tok->str() + "() leads to undefined result");
     } else
         reportError(tok, Severity::error, "wrongmathcall", "Passing value " " to " "() leads to undefined result");
 }
@@ -2117,30 +2117,30 @@ void CheckOther::checkIncorrectStringCompare()
 {
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
         if (Token::Match(tok, ". substr ( %any% , %num% ) ==|!= %str%")) {
-            size_t clen = MathLib::toLongNumber(tok->tokAt(5)->str());
+            size_t clen = MathLib::toLongNumber(tok->strAt(5));
             size_t slen = Token::getStrLength(tok->tokAt(8));
             if (clen != slen) {
-                incorrectStringCompareError(tok->next(), "substr", tok->tokAt(8)->str(), tok->tokAt(5)->str());
+                incorrectStringCompareError(tok->next(), "substr", tok->strAt(8), tok->strAt(5));
             }
         }
         if (Token::Match(tok, "%str% ==|!= %var% . substr ( %any% , %num% )")) {
-            size_t clen = MathLib::toLongNumber(tok->tokAt(8)->str());
+            size_t clen = MathLib::toLongNumber(tok->strAt(8));
             size_t slen = Token::getStrLength(tok);
             if (clen != slen) {
-                incorrectStringCompareError(tok->next(), "substr", tok->str(), tok->tokAt(8)->str());
+                incorrectStringCompareError(tok->next(), "substr", tok->str(), tok->strAt(8));
             }
         }
         if (Token::Match(tok, "&&|%oror% %str% &&|%oror%|)")) {
             // assert(condition && "debug message") would be considered a fp.
-            if (tok->str() == "&&" && tok->tokAt(2)->str() == ")" && tok->tokAt(2)->link()->previous()->str() == "assert")
+            if (tok->str() == "&&" && tok->strAt(2) == ")" && tok->tokAt(2)->link()->previous()->str() == "assert")
                 continue;
-            incorrectStringBooleanError(tok->tokAt(1), tok->tokAt(1)->str());
+            incorrectStringBooleanError(tok->tokAt(1), tok->strAt(1));
         }
         if (Token::Match(tok, "if|while|assert ( %str% &&|%oror%|)")) {
             // assert("debug message" && condition) would be considered a fp.
-            if (tok->tokAt(3)->str() == "&&" && tok->str() == "assert")
+            if (tok->strAt(3) == "&&" && tok->str() == "assert")
                 continue;
-            incorrectStringBooleanError(tok->tokAt(2), tok->tokAt(2)->str());
+            incorrectStringBooleanError(tok->tokAt(2), tok->strAt(2));
         }
     }
 }
diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index 684909eda..bf913c997 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -90,7 +90,7 @@ void CheckStl::iterators()
 
                 // If insert/erase is used on different container then
                 // report an error
-                if (tok2->varId() != containerId && tok2->tokAt(5)->str() != ".") {
+                if (tok2->varId() != containerId && tok2->strAt(5) != ".") {
                     // skip error message if container is a set..
                     if (tok2->varId() > 0) {
                         const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
@@ -203,12 +203,12 @@ void CheckStl::mismatchingContainers()
 
         // TODO: If iterator variables are used instead then there are false negatives.
         if (Token::Match(tok, pattern2.c_str()) && algorithm2.find(tok->strAt(2)) != algorithm2.end()) {
-            if (tok->tokAt(4)->str() != tok->tokAt(10)->str()) {
+            if (tok->strAt(4) != tok->strAt(10)) {
                 mismatchingContainersError(tok);
             }
             tok = tok->tokAt(15);
         } else if (Token::Match(tok, pattern22.c_str()) && algorithm22.find(tok->strAt(2)) != algorithm22.end()) {
-            if (tok->tokAt(4)->str() != tok->tokAt(10)->str() || tok->tokAt(16)->str() != tok->tokAt(22)->str()) {
+            if (tok->strAt(4) != tok->strAt(10) || tok->strAt(16) != tok->strAt(22)) {
                 mismatchingContainersError(tok);
             }
             tok = tok->tokAt(27);
@@ -225,7 +225,7 @@ void CheckStl::mismatchingContainers()
                     break;
             }
             if (tok2 && Token::Match(tok2, pattern1x1_2.c_str())) {
-                if (tok->tokAt(4)->str() != tok2->tokAt(1)->str()) {
+                if (tok->strAt(4) != tok2->strAt(1)) {
                     mismatchingContainersError(tok);
                 }
                 tok = tok2->tokAt(6);
@@ -277,7 +277,7 @@ void CheckStl::stlOutOfBounds()
                         if (Token::simpleMatch(tok3->next(), ". size ( )"))
                             break;
                         else if (Token::Match(tok3->next(), "[ %varid% ]", numId))
-                            stlOutOfBoundsError(tok3, tok3->tokAt(2)->str(), tok3->str());
+                            stlOutOfBoundsError(tok3, tok3->strAt(2), tok3->str());
                     }
                 }
                 break;
@@ -455,8 +455,8 @@ void CheckStl::erase()
                 }
 
                 if (Token::Match(tok2, "%var% = %var% . begin|rbegin|cbegin|crbegin ( ) ; %var% != %var% . end|rend|cend|crend ( )") &&
-                    tok2->str() == tok2->tokAt(8)->str() &&
-                    tok2->tokAt(2)->str() == tok2->tokAt(10)->str()) {
+                    tok2->str() == tok2->strAt(8) &&
+                    tok2->strAt(2) == tok2->strAt(10)) {
                     EraseCheckLoop::checkScope(this, tok2);
                     break;
                 }
@@ -546,7 +546,7 @@ void CheckStl::pushback()
         if (iteratorid == 0)
             continue;
 
-        if (iteratorDeclaredInsideLoop && tok->tokAt(4)->str() == "=") {
+        if (iteratorDeclaredInsideLoop && tok->strAt(4) == "=") {
             // skip "> :: iterator|const_iterator"
             tok = tok->tokAt(3);
         }
@@ -878,7 +878,7 @@ void CheckStl::redundantCondition()
                            "}|}|";
     const Token *tok = Token::findmatch(_tokenizer->tokens(), pattern);
     while (tok) {
-        bool b(tok->tokAt(15)->str() == "{");
+        bool b(tok->strAt(15) == "{");
 
         // Get tokens for the fields %var% and %any%
         const Token *var1 = tok->tokAt(2);
@@ -1201,8 +1201,8 @@ void CheckStl::uselessCalls()
         } else if (Token::Match(tok, "%var% . substr ( )")) {
             uselessCallsSubstrError(tok, tok->str());
         } else if (Token::Match(tok, "%var% . substr ( 0")) {
-            if (tok->tokAt(5)->str() == ")" ||
-                tok->tokAt(3)->link()->tokAt(-1)->str() == "npos")
+            if (tok->strAt(5) == ")" ||
+                tok->tokAt(3)->link()->strAt(-1) == "npos")
                 uselessCallsSubstrError(tok, tok->str());
         }
     }
diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index 2db538ff9..345d712d4 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -548,7 +548,7 @@ private:
 
             if (Token::Match(tok.next(), "= malloc|kmalloc") || Token::simpleMatch(tok.next(), "= new char [")) {
                 alloc_pointer(checks, tok.varId());
-                if (tok.tokAt(3)->str() == "(")
+                if (tok.strAt(3) == "(")
                     return tok.tokAt(3);
             }
 
diff --git a/lib/checkunusedvar.cpp b/lib/checkunusedvar.cpp
index c081f620b..760f61209 100644
--- a/lib/checkunusedvar.cpp
+++ b/lib/checkunusedvar.cpp
@@ -409,7 +409,7 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
         int start = 1;
 
         // search for '='
-        while (tok->tokAt(start)->str() != "=")
+        while (tok->strAt(start) != "=")
             start++;
 
         start++;
@@ -426,21 +426,21 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
                 variables.use(tok->tokAt(start)->varId());   // use = read + write
 
             // check for C style cast
-            if (tok->tokAt(start)->str() == "(") {
-                if (tok->tokAt(start + 1)->str() == "const")
+            if (tok->strAt(start) == "(") {
+                if (tok->strAt(start + 1) == "const")
                     offset++;
 
                 if (Token::Match(tok->tokAt(start + 1 + offset), "struct|union"))
                     offset++;
 
-                if (tok->tokAt(start + 2 + offset)->str() == "*")
+                if (tok->strAt(start + 2 + offset) == "*")
                     offset++;
 
-                if (tok->tokAt(start + 3 + offset)->str() == "&") {
+                if (tok->strAt(start + 3 + offset) == "&") {
                     addressOf = true;
                     next = start + 4 + offset;
-                } else if (tok->tokAt(start + 3 + offset)->str() == "(") {
-                    if (tok->tokAt(start + 4 + offset)->str() == "&") {
+                } else if (tok->strAt(start + 3 + offset) == "(") {
+                    if (tok->strAt(start + 4 + offset) == "&") {
                         addressOf = true;
                         next = start + 5 + offset;
                     } else
@@ -450,18 +450,18 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
             }
 
             // check for C++ style cast
-            else if (tok->tokAt(start)->str().find("cast") != std::string::npos &&
-                     tok->tokAt(start + 1)->str() == "<") {
-                if (tok->tokAt(start + 2)->str() == "const")
+            else if (tok->strAt(start).find("cast") != std::string::npos &&
+                     tok->strAt(start + 1) == "<") {
+                if (tok->strAt(start + 2) == "const")
                     offset++;
 
                 if (Token::Match(tok->tokAt(start + 2 + offset), "struct|union"))
                     offset++;
 
-                if (tok->tokAt(start + 3 + offset)->str() == "*")
+                if (tok->strAt(start + 3 + offset) == "*")
                     offset++;
 
-                if (tok->tokAt(start + 5 + offset)->str() == "&") {
+                if (tok->strAt(start + 5 + offset) == "&") {
                     addressOf = true;
                     next = start + 6 + offset;
                 } else
@@ -475,10 +475,10 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
 
             // no cast
             else {
-                if (tok->tokAt(start)->str() == "&") {
+                if (tok->strAt(start) == "&") {
                     addressOf = true;
                     next = start + 1;
-                } else if (tok->tokAt(start)->str() == "new")
+                } else if (tok->strAt(start) == "new")
                     return 0;
                 else
                     next = start;
@@ -538,7 +538,7 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
                             }
 
                             variables.alias(varid1, varid2, replace);
-                        } else if (tok->tokAt(next + 1)->str() == "?") {
+                        } else if (tok->strAt(next + 1) == "?") {
                             if (var2->_type == Variables::reference)
                                 variables.readAliases(varid2);
                             else
@@ -548,7 +548,7 @@ static int doAssignment(Variables &variables, const Token *tok, bool dereference
                 } else if (var1->_type == Variables::reference) {
                     variables.alias(varid1, varid2, true);
                 } else {
-                    if (var2->_type == Variables::pointer && tok->tokAt(next + 1)->str() == "[")
+                    if (var2->_type == Variables::pointer && tok->strAt(next + 1) == "[")
                         variables.readAliases(varid2);
 
                     variables.read(varid2);
@@ -714,7 +714,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
 
                 if (tok->isStandardType() || isRecordTypeWithoutSideEffects(tok->next())) {
                     variables.addVar(tok->next(), Variables::standard, info,
-                                     tok->tokAt(2)->str() == "=" || isStatic);
+                                     tok->strAt(2) == "=" || isStatic);
                 }
                 tok = tok->next();
             }
@@ -757,7 +757,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 tok = tok->next();
 
                 variables.addVar(tok->next(), Variables::standard, info,
-                                 tok->tokAt(2)->str() == "=" || isStatic);
+                                 tok->strAt(2) == "=" || isStatic);
                 tok = tok->next();
             }
 
@@ -796,7 +796,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                     const Token * const nametok = tok->tokAt(isPointer ? 2 : 1);
 
                     variables.addVar(nametok, isPointer ? Variables::pointerArray : Variables::array, info,
-                                     nametok->tokAt(4)->str() == "=" || isStatic);
+                                     nametok->strAt(4) == "=" || isStatic);
 
                     // check for reading array size from local variable
                     if (nametok->tokAt(2)->varId() != 0)
@@ -838,7 +838,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                     else
                         type = Variables::reference;
 
-                    bool written = tok->tokAt(3)->str() == "=";
+                    bool written = tok->strAt(3) == "=";
 
                     variables.addVar(tok->tokAt(2), type, info, written || isStatic);
 
@@ -865,7 +865,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                     tok = tok->next();
 
                 if (tok->str() != "return") {
-                    bool written = tok->tokAt(4)->str() == "=";
+                    bool written = tok->strAt(4) == "=";
 
                     variables.addVar(tok->tokAt(3), Variables::pointerPointer, info, written || isStatic);
 
@@ -972,7 +972,7 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 if (tok->str() != "return") {
                     variables.addVar(tok->tokAt(2),
                                      tok->next()->str() == "*" ? Variables::pointerArray : Variables::referenceArray, info,
-                                     tok->tokAt(6)->str() == "=" || isStatic);
+                                     tok->strAt(6) == "=" || isStatic);
 
                     // check for reading array size from local variable
                     if (tok->tokAt(4)->varId() != 0)
@@ -995,8 +995,8 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                     tok = tok->next();
 
                 variables.addVar(tok->tokAt(3),
-                                 tok->tokAt(2)->str() == "*" ? Variables::pointerArray : Variables::referenceArray, info,
-                                 tok->tokAt(7)->str() == "=" || isStatic);
+                                 tok->strAt(2) == "*" ? Variables::pointerArray : Variables::referenceArray, info,
+                                 tok->strAt(7) == "=" || isStatic);
 
                 // check for reading array size from local variable
                 if (tok->tokAt(5)->varId() != 0)
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 9b7ec063d..3c2427b66 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -375,7 +375,7 @@ SymbolDatabase::SymbolDatabase(const Tokenizer *tokenizer, const Settings *setti
 
                         // class destructor
                         else if (tok->previous() && tok->previous()->str() == "~" &&
-                                 tok->tokAt(-2) && tok->tokAt(-2)->str() == "::")
+                                 tok->tokAt(-2) && tok->strAt(-2) == "::")
                             addFunction(&scope, &tok, argStart);
 
                         // regular function
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 7b31d660c..d68523b6a 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -1010,7 +1010,7 @@ void Tokenizer::simplifyTypedef()
         }
 
         // check for template
-        if (tok->tokAt(offset)->str() == "<") {
+        if (tok->strAt(offset) == "<") {
             unsigned int level = 0;
             unsigned int paren = 0;
             typeEnd = tok->tokAt(offset + 1);
@@ -1050,7 +1050,7 @@ void Tokenizer::simplifyTypedef()
 
         // check for pointers and references
         while (Token::Match(tok->tokAt(offset), "*|&|const"))
-            pointers.push_back(tok->tokAt(offset++)->str());
+            pointers.push_back(tok->strAt(offset++));
 
         // check for invalid input
         if (!tok->tokAt(offset)) {
@@ -1063,7 +1063,7 @@ void Tokenizer::simplifyTypedef()
             typeName = tok->tokAt(offset++);
 
             // check for array
-            if (tok->tokAt(offset) && tok->tokAt(offset)->str() == "[") {
+            if (tok->tokAt(offset) && tok->strAt(offset) == "[") {
                 arrayStart = tok->tokAt(offset);
 
                 bool atEnd = false;
@@ -1073,9 +1073,9 @@ void Tokenizer::simplifyTypedef()
 
                     if (!tok->tokAt(offset + 1))
                         return; // invalid input
-                    else if (tok->tokAt(offset + 1)->str() == ";")
+                    else if (tok->strAt(offset + 1) == ";")
                         atEnd = true;
-                    else if (tok->tokAt(offset)->str() == "]")
+                    else if (tok->strAt(offset) == "]")
                         atEnd = true;
                     else
                         ++offset;
@@ -1161,7 +1161,7 @@ void Tokenizer::simplifyTypedef()
         // function: typedef ... ( .... type )( ... );
         //           typedef ... (( .... type )( ... ));
         //           typedef ... ( * ( .... type )( ... ));
-        else if ((tok->tokAt(offset)->str() == "(" &&
+        else if ((tok->strAt(offset) == "(" &&
                   Token::Match(tok->tokAt(offset)->link()->previous(), "%type% ) (") &&
                   Token::Match(tok->tokAt(offset)->link()->next()->link(), ") const|volatile|;")) ||
                  (Token::simpleMatch(tok->tokAt(offset), "( (") &&
@@ -1260,8 +1260,8 @@ void Tokenizer::simplifyTypedef()
 
         // pointer/reference to array
         else if (Token::Match(tok->tokAt(offset), "( *|& %type% ) [")) {
-            ptrToArray = (tok->tokAt(offset + 1)->str() == "*");
-            refToArray = (tok->tokAt(offset + 1)->str() == "&");
+            ptrToArray = (tok->strAt(offset + 1) == "*");
+            refToArray = (tok->strAt(offset + 1) == "&");
             typeName = tok->tokAt(offset + 2);
             arrayStart = tok->tokAt(offset + 4);
             arrayEnd = arrayStart->link();
@@ -1761,12 +1761,12 @@ void Tokenizer::simplifyTypedef()
                 pointers.clear();
 
                 while (Token::Match(tok->tokAt(offset), "*|&"))
-                    pointers.push_back(tok->tokAt(offset++)->str());
+                    pointers.push_back(tok->strAt(offset++));
 
                 if (Token::Match(tok->tokAt(offset), "%type%")) {
                     typeName = tok->tokAt(offset++);
 
-                    if (tok->tokAt(offset) && tok->tokAt(offset)->str() == "[") {
+                    if (tok->tokAt(offset) && tok->strAt(offset) == "[") {
                         arrayStart = tok->tokAt(offset);
 
                         bool atEnd = false;
@@ -1776,9 +1776,9 @@ void Tokenizer::simplifyTypedef()
 
                             if (!tok->tokAt(offset + 1))
                                 return; // invalid input
-                            else if (tok->tokAt(offset + 1)->str() == ";")
+                            else if (tok->strAt(offset + 1) == ";")
                                 atEnd = true;
-                            else if (tok->tokAt(offset)->str() == "]")
+                            else if (tok->strAt(offset) == "]")
                                 atEnd = true;
                             else
                                 ++offset;
@@ -2984,7 +2984,7 @@ void Tokenizer::simplifyTemplatesInstantiate(const Token *tok,
         }
         return;
     }
-    if ((tok->tokAt(namepos)->str() == "*" || tok->tokAt(namepos)->str() == "&"))
+    if ((tok->strAt(namepos) == "*" || tok->strAt(namepos) == "&"))
         ++namepos;
 
     // name of template function/class..
@@ -4724,7 +4724,7 @@ void Tokenizer::removeRedundantFor()
             // Same variable name..
             const std::string varname(tok->strAt(3));
             const unsigned int varid(tok->tokAt(3)->varId());
-            if (varname != tok->tokAt(7)->str())
+            if (varname != tok->strAt(7))
                 continue;
             const Token *vartok = tok->tokAt(11);
             if (vartok->str() == "++")
@@ -6794,7 +6794,7 @@ bool Tokenizer::simplifyKnownVariablesSimplify(Token **tok2, Token *tok3, unsign
             --indentlevel3;
             if (indentlevel3 < indentlevel) {
                 if (Token::Match((*tok2)->tokAt(-7), "%type% * %var% ; %var% = & %var% ;") &&
-                    (*tok2)->tokAt(-5)->str() == (*tok2)->strAt(-3)) {
+                    (*tok2)->strAt(-5) == (*tok2)->strAt(-3)) {
                     (*tok2) = (*tok2)->tokAt(-4);
                     Token::eraseTokens((*tok2), (*tok2)->tokAt(5));
                 }