Re: [boost] [variant] Please vote for behavior (Was: Basic rvalue and C++11 features seupport)

Subject: Re: [boost] [variant] Please vote for behavior (Was: Basic rvalue and C++11 features seupport)
From: Paul Smith (pl.smith.mail_at_[hidden])
Date: 2013-01-21 12:06:32

On Mon, Jan 21, 2013 at 6:12 PM, Joel de Guzman <djowel_at_[hidden]> wrote:
> This notion of a "valid" state
> is not clear to begin with anyway and many say it depends on the library
> to define what "valid" means. The case of NaN is a very clear example
> of a perfectly "valid" state similar to what we have here.

I'm not sure what the NaN example supposed to convey? I think Nevin
brought it up to show that std::less<double> is not a weak partial
order. And guess what, it technically isn't! Try to put NaNs inside an
associative container and watch the world collapse. The big difference
is that no operation on non-NaNs that the container performs ever
produces a NaN out of thin air.

--
Paul Smith