diff --git a/app/actions.cpp b/app/actions.cpp
index 6b67bcb4ab..56ba832b5f 100644
--- a/app/actions.cpp
+++ b/app/actions.cpp
@@ -1864,7 +1864,7 @@ int renameFile(std::string& newPath, const tm* tm) {
           std::cout << Params::instance().progname() << ": " << _("File") << " `" << newPath << "' "
                     << _("exists. [O]verwrite, [r]ename or [s]kip?") << " ";
           std::cin >> s;
-          switch (s.at(0)) {
+          switch (s.front()) {
             case 'o':
             case 'O':
               go = false;
@@ -1915,7 +1915,7 @@ int dontOverwrite(const std::string& path) {
     std::cout << Params::instance().progname() << ": " << _("Overwrite") << " `" << path << "'? ";
     std::string s;
     std::cin >> s;
-    if (s.at(0) != 'y' && s.at(0) != 'Y')
+    if (s.front() != 'y' && s.front() != 'Y')
       return 1;
   }
   return 0;
diff --git a/samples/iptctest.cpp b/samples/iptctest.cpp
index 3a1b872e09..92c1fb1bc7 100644
--- a/samples/iptctest.cpp
+++ b/samples/iptctest.cpp
@@ -46,7 +46,7 @@ int main(int argc, char* const argv[]) {
 }
 
 bool processLine(const std::string& line, int num, IptcData& iptcData) {
-  switch (line.at(0)) {
+  switch (line.front()) {
     case 'a':
     case 'A':
       processAdd(line, num, iptcData);
@@ -64,7 +64,7 @@ bool processLine(const std::string& line, int num, IptcData& iptcData) {
       return false;
     default:
       std::ostringstream os;
-      os << "Unknown command (" << line.at(0) << ") at line " << num;
+      os << "Unknown command (" << line.front() << ") at line " << num;
       throw Error(ErrorCode::kerErrorMessage, os.str());
   }
   return true;
@@ -86,7 +86,7 @@ void processAdd(const std::string& line, int num, IptcData& iptcData) {
 
   std::string data(line.substr(dataStart));
   // if data starts and ends with quotes, remove them
-  if (data.at(0) == '\"' && data.at(data.size() - 1) == '\"') {
+  if (data.front() == '\"' && data.back() == '\"') {
     data = data.substr(1, data.size() - 2);
   }
   TypeId type = IptcDataSets::dataSetType(iptcKey.tag(), iptcKey.record());
@@ -133,7 +133,7 @@ void processModify(const std::string& line, int num, IptcData& iptcData) {
 
   std::string data(line.substr(dataStart));
   // if data starts and ends with quotes, remove them
-  if (data.at(0) == '\"' && data.at(data.size() - 1) == '\"') {
+  if (data.front() == '\"' && data.back() == '\"') {
     data = data.substr(1, data.size() - 2);
   }
   TypeId type = IptcDataSets::dataSetType(iptcKey.tag(), iptcKey.record());
diff --git a/src/basicio.cpp b/src/basicio.cpp
index 8d92d9c90d..a69b43c0a2 100644
--- a/src/basicio.cpp
+++ b/src/basicio.cpp
@@ -136,12 +136,12 @@ int FileIo::Impl::switchMode(OpMode opMode) {
     case opRead:
       // Flush if current mode allows reading, else reopen (in mode "r+b"
       // as in this case we know that we can write to the file)
-      if (openMode_.at(0) == 'r' || openMode_.at(1) == '+')
+      if (openMode_.front() == 'r' || openMode_.at(1) == '+')
         reopen = false;
       break;
     case opWrite:
       // Flush if current mode allows writing, else reopen
-      if (openMode_.at(0) != 'r' || openMode_.at(1) == '+')
+      if (openMode_.front() != 'r' || openMode_.at(1) == '+')
         reopen = false;
       break;
     case opSeek:
@@ -499,7 +499,7 @@ size_t FileIo::tell() const {
 
 size_t FileIo::size() const {
   // Flush and commit only if the file is open for writing
-  if (p_->fp_ && (p_->openMode_.at(0) != 'r' || p_->openMode_.at(1) == '+')) {
+  if (p_->fp_ && (p_->openMode_.front() != 'r' || p_->openMode_.at(1) == '+')) {
     std::fflush(p_->fp_);
 #ifdef _MSC_VER
     // This is required on msvcrt before stat after writing to a file
diff --git a/src/sigmamn_int.cpp b/src/sigmamn_int.cpp
index 69d8ea8546..c7d3b7d7d9 100644
--- a/src/sigmamn_int.cpp
+++ b/src/sigmamn_int.cpp
@@ -82,7 +82,7 @@ std::ostream& SigmaMakerNote::printStripLabel(std::ostream& os, const Value& val
 }
 
 std::ostream& SigmaMakerNote::print0x0008(std::ostream& os, const Value& value, const ExifData*) {
-  switch (value.toString().at(0)) {
+  switch (value.toString().front()) {
     case 'P':
       os << _("Program");
       break;
@@ -103,7 +103,7 @@ std::ostream& SigmaMakerNote::print0x0008(std::ostream& os, const Value& value,
 }
 
 std::ostream& SigmaMakerNote::print0x0009(std::ostream& os, const Value& value, const ExifData*) {
-  switch (value.toString().at(0)) {
+  switch (value.toString().front()) {
     case 'A':
       os << _("Average");
       break;
diff --git a/src/tiffvisitor_int.cpp b/src/tiffvisitor_int.cpp
index c880eb1bb0..15263dd794 100644
--- a/src/tiffvisitor_int.cpp
+++ b/src/tiffvisitor_int.cpp
@@ -357,7 +357,7 @@ void TiffDecoder::decodeCanonAFInfo(const TiffEntryBase* object) {
     uint.push_back(static_cast<uint16_t>(object->pValue()->toInt64(i)));
   }
   // Check this is AFInfo2 (ints[0] = bytes in object)
-  if (ints.at(0) != static_cast<int16_t>(object->pValue()->count()) * 2)
+  if (ints.front() != static_cast<int16_t>(object->pValue()->count()) * 2)
     return;
 
   std::string familyGroup(std::string("Exif.") + groupName(object->group()) + ".");