问题
I've seen N3690, N4140, and N4296 mentioned in various places. I'm guessing it's N4140 because that was released in late 2014. N4296 seems to have stuff that isn't in C++14, like fold expressions.
回答1:
N3690 is an old committee draft for C++14; massive changes have been made since then (e.g., the removal of <optional> and <dynarray>), and it shouldn't be used for anything other than perhaps standard archaeology.
N3936 is the version that's sent out for final balloting (well, the version that's actually sent out is N3937, but the difference is basically a fancy cover page). That, with some minor editorial fixes, became the C++14 IS.
N4140 is to C++14 what N3337 is to C++11 - C++14 plus some editorial changes.
N4296 is a later working draft incorporating additional proposals voted into the standard.
来源：https://stackoverflow.com/questions/29115656/which-draft-is-closest-to-the-c14-standard