Re: [boost] boost::rational test program

From: Stephen Silver (boost_at_[hidden])
Date: 2001-01-21 18:43:31

Paul Moore wrote:

> > http://www.argentum.freeserve.co.uk/cpp/rational.zip
>
> This is nice. Would you have any objections to me including it in
> the rational library, as a regression test?

No objections.  I already gave it a Boost-compliant copyright notice.

> lcm bugs fixed. However, I think you are mistaken over the 
> operator>> errors - remember that >> consumes as much input as 
> it can, only setting the error state if it cannot construct a valid value.
>
> Your example
>
>     std::istringstream iss("57A");
>     iss >> r0;
>
> consumes "57". This is a valid representation of a rational, namely 
> 57/1, so r0 is set to this, and the stream is in a good state.

OK.  But in that case the documentation needs changing, because it
says:

    The external representation of a rational is two integers,
    separated by a slash (/). On input, there must be no space
    between the numerator and the slash. 

which seems to imply that anything without a / is not a valid input.
(Also, the above requirement seems lacking in symmetry.  Would it not
be better if it either allowed spaces both sides of the / or disallowed
them both sides?)

Stephen