Fix cppcheck issues: passedByValue

samples/exiv2json.cpp

@@ -101,7 +101,7 @@ Jzon::Node& recursivelyBuildTree(Jzon::Node& root,Tokens& tokens,size_t k)
 }
 
 // build the json tree for this key.  return location and discover the name
-Jzon::Node& objectForKey(const std::string Key,Jzon::Object& root,std::string& name,Exiv2::StringSet* pNS=NULL)
+Jzon::Node& objectForKey(const std::string& Key,Jzon::Object& root,std::string& name,Exiv2::StringSet* pNS=NULL)
 {
     // Parse the key
     Tokens      tokens ;

samples/geotag.cpp

@@ -467,7 +467,7 @@ string getExifTime(const time_t t)
     return result ;
 }
 
-std::string makePath(std::string dir,std::string file)
+std::string makePath(const std::string& dir, const std::string& file)
 {
     return dir + std::string(EXV_SEPARATOR_STR) + file ;
 }
@@ -607,7 +607,7 @@ bool readImage(const char* path,Options& /* options */)
     return bResult ;
 }
 
-time_t readImageTime(std::string path,std::string* pS=NULL)
+time_t readImageTime(const std::string& path,std::string* pS=NULL)
 {
     using namespace Exiv2;
 
@@ -753,7 +753,7 @@ int parseTZ(const char* adjust)
     return (3600*h)+(60*m);
 }
 
-bool mySort(std::string a,std::string b)
+bool mySort(const std::string& a, const std::string& b)
 {
     time_t A = readImageTime(a);
     time_t B = readImageTime(b);

src/exiv2.cpp

@@ -247,7 +247,7 @@ void Params::usage(std::ostream& os) const
        << _("Manipulate the Exif metadata of images.\n");
 }
 
-std::string Params::printTarget(std::string before,int target,bool bPrint,std::ostream& out)
+std::string Params::printTarget(const std::string &before, int target, bool bPrint, std::ostream& out)
 {
     std::string t;
     if ( target & Params::ctExif       ) t+= 'e';

src/exiv2app.hpp

@@ -344,7 +344,7 @@ public:
     void version(bool verbose =false, std::ostream& os =std::cout) const;
 
     //! Print target_
-    static std::string printTarget(std::string before,int target,bool bPrint=false,std::ostream& os=std::cout);
+    static std::string printTarget(const std::string& before,int target,bool bPrint=false,std::ostream& os=std::cout);
 
     //! getStdin binary data read from stdin to DataBuf
     /*