[boost] Re: MemberFunctionCompare part 2

From: jsiek_at_[hidden]
Date: 2000-01-15 15:05:08

Hi Jim,

Jim Argeropoulos writes:
 > First and most important to me, it doesn't solve the problem of comparing by
 > more than one attribute. You can't chain multiple calls to compose_f_gx_hy()
 > with logical_and or logical_or because they require the same type.

This is the fault of the definition of
logical_and/logical_not. Actually, most of std functors have this
problem, I agree it is annoying. Perhaps the thing to do is create
versions of the std functors that allow the operands to be different
types.

 > Second, few practicing programmers are going to figure it out. If we call it
 > a solution I would like to see some helper functions for it. Of the 30
 > programmers I work with I would only expect one other to ever figure out how
 > to put compose_f_gx_hy() to use on their own. Its just too abstract for
 > them. Maybe in a few years, but not today. Those who partake in this mailing
 > list think at a different level than the average programmer.

You have a good point. The right implementation approach would be to
use the compose library to implement your library. A few typedefs and
some small functions would be all that it would take. Also such
an implementation would be a good resource for people to look at and
learn about programming with functors.

Cheers,

Jeremy

PS. BTW, which compiler do you use?