[trac613] pass parameters by reference instead of a copy of obj when possible

src/lib/config/tests/ccsession_unittests.cc

@@ -31,7 +31,7 @@ using namespace std;
 
 namespace {
 std::string
-ccspecfile(const std::string name) {
+ccspecfile(const std::string& name) {
     return (std::string(TEST_DATA_PATH) + "/" + name);
 }
 

src/lib/config/tests/module_spec_unittests.cc

@@ -23,7 +23,7 @@
 using namespace isc::data;
 using namespace isc::config;
 
-std::string specfile(const std::string name) {
+std::string specfile(const std::string& name) {
     return (std::string(TEST_DATA_PATH) + "/" + name);
 }
 

src/lib/log/strutil.cc

@@ -62,7 +62,7 @@ trim(const string& instring) {
 // another dependency on a Boost library.
 
 vector<string>
-tokens(const std::string text, const std::string& delim) {
+tokens(const std::string& text, const std::string& delim) {
     vector<string> result;
 
     // Search for the first non-delimiter character

src/lib/log/strutil.h

@@ -71,7 +71,7 @@ std::string trim(const std::string& instring);
 /// \param delim Delimiter characters
 ///
 /// \return Vector of tokens.
-std::vector<std::string> tokens(const std::string text,
+std::vector<std::string> tokens(const std::string& text,
         const std::string& delim = std::string(" \t\n"));