std::pair conversion

Signed-off-by: Rosen Penev <rosenp@gmail.com>

app/exiv2.cpp

@@ -1437,9 +1437,10 @@ bool parseLine(ModifyCmd& modifyCmd, const std::string& line, int num) {
 
 CmdId commandId(const std::string& cmdString) {
   int i = 0;
-  for (; cmdIdAndString[i].cmdId_ != invalidCmdId && cmdIdAndString[i].cmdString_ != cmdString; ++i) {
+  while (cmdIdAndString[i].first != invalidCmdId && cmdIdAndString[i].second != cmdString) {
+    ++i;
   }
-  return cmdIdAndString[i].cmdId_;
+  return cmdIdAndString[i].first;
 }
 
 std::string parseEscapes(const std::string& input) {

app/exiv2app.hpp

@@ -51,11 +51,7 @@ struct ModifyCmd {
 //! Container for modification commands
 using ModifyCmds = std::vector<ModifyCmd>;
 //! Structure to link command identifiers to strings
-struct CmdIdAndString {
+using CmdIdAndString = std::pair<CmdId, std::string>;
-  CmdId cmdId_;            //!< Commands identifier
-  std::string cmdString_;  //!< Command string
-};
-
 /*!
   @brief Implements the command line handling for the program.