[boost] Two points about the Named parameters library

From: Joaquín Mª López Muñoz (joaquin_at_[hidden])
Date: 2004-11-16 03:32:57

Hello,

This is not a review of the Named params library. I'd just want
to make the following two points about it:

1. Some have considered this library as a means to gain experience
about named parameters interfaces for possible inclusion into the
standard as a built-in facility. I think this won't happen, since this
issue has already been discussed (and rejected) prior to C++98.
The library does not raise (AFAIK) any new issue about the
suitability of such interfaces, so why should the comittee change
their minds.
So, we'd better consider named_params as a utility on its own,
without hoping for future built-in support.

2. I think the docs miss an important point. Consider a final user
exposed to a named_params-powered interface. Of course this user
is not concerned about the implementation of the interface, or about
the named_params lib, for that matter. Instead, she should be presented
the interface as if named params were a built-in facility. A
possibility:

void foo(int :x:=0,int :y:=0,std::string :msg:="")
foo does so and so...
:x:,:y: and :msg: are named params that the user can resort to in order
to subvert the traditional argument-by-position invokation interface.
For instace:
foo(msg="hello");

I don't claim this particular documentation example is any good (in
fact,
I found it rather bad), but I hope you get the idea. named_params docs
are the perfect place to propose and "standardize" a general syntax and
wording to document named parameter interfaces for the final user.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo