Static analyser cppcheck says: 1. bolt/include/bolt/Passes/StokeInfo.h:90:24: performance: Range variable 'S' should be declared as const reference. [iterateByValue] Source code is for (std::string S : DefIn) Outfile << "%" << S << " "; 2. bolt/include/bolt/Passes/StokeInfo.h:93:24: performance: Range variable 'S' should be declared as const reference. [iterateByValue] Duplicate.