https://github.com/kwatch/template-engine-benchmarks/blob/master/others/string-concat/cpp/bench_strcat.cpp
ʂ̃TCgɃWv悤ƂĂ܂BXΏL̃NNbNĂ
UPLIFTōLȂő̌܂傤IKȉ{Ct܂I