http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2927.pdf
ʂ̃TCgɃWv悤ƂĂ܂BXΏL̃NNbNĂ
UPLIFTōLȂő̌܂傤IKȉ{Ct܂I