[boost] Re: Including abs() in rational.hpp

From: Gabriel Dos Reis (Gabriel.Dos-Reis_at_[hidden])
Date: 1999-12-17 18:08:49

Alan Griffiths <alan_at_[hidden]> writes:

[...]

| >> /2/ Require any client code that references an abs function in a class
| >> where an abs member function exists to use a proxy function like: 
| >> 
| >>     template<typename number_type> 
| >>     number_type proxy_abs(number_type x)
| >>     { using std::abs; return abs(x); )
| >> 
| >> (I guess this is what you intend.  However, I think this would be a
| >> maintenance disaster.)
| >
| >This is what I do (modulo compiler bugs) in the rational class. It is nasty,
| >but I don't see it as a big issue. Then again, I don't view the rational
| >class as "client" code - it's library code (as will be all generic stuff, in
| >principle), and as such needs to take careful account of such issues.
| 
| No but rational<> should appear as much like a fundamental type as
| possible to the eventual user.  That user should be able to say
| "std::abs(a_rational)".

It is wrong to let a user believe that rational<> is a fundamental type.

-- Gaby