[boost] Re: Rational Numbers - abs() again

From: Beman Dawes (beman_at_[hidden])
Date: 1999-12-17 20:29:36

At 10:08 PM 12/17/99 -0000, Paul Moore wrote:

>Right. Attached is the final version of rational. I say final, but
the abs()
>stuff is *still* fairly fragile. It works on MSVC, but that's all I
can say. 

>I would appreciate comments on how other compilers fare.

Paul,

Here is a report on compiling rational_example.cpp with Metrowerks
CodeWarrior 5.2:

*  #ifdef _MSC_VER is true, causing the Microsoft hacks to be
invoked, which of course fail with the more standards conforming CW
compiler.

Several companies (Metrowerks, Intel, at least, probably more)
predefine _MSC_VER in an attempt to be compatible.  Sigh. 

*  After commenting out the above, tried again and got:

Error   : illegal access to protected/private member
 (instantiating: 'boost::?$abs_at_H(const boost::rational<int> &)')
rational.hpp line 299       return rational<IntType>(abs(r.num),
r.den);

(r.num) was underlined.

*  After commenting out "private:" to hack around the above, the
compile was clean.

*  Ran apparently OK with the output:

1/2+1/2=1/1
1/1-1/2=1/2
2/1*1/2=1/1
1/1/1/2=2/1
abs(-1/2)=1/2
2 * 2147483647/2=2147483647 (rational: 2147483647/1)
pi = 3.14286 (nearly)

Sorry; I was pressed for time and did nothing more.

Hope the above helps.

--Beman