Re: [boost] Debug/Stream Libraries?

From: Jesse Jones (jesjones_at_[hidden])
Date: 2001-11-26 18:39:48

At 4:28 PM -0500 11/26/01, David A. Greene wrote:

>Ok, I don't understand then what you mean by "take optional
>arguments...to modify the formatting."  What formatting are you
>modifying?

It's the ToStr methods:
    LOG(NULL, "pi = ", ToStr(pi, 3));

would print pi to 3 decimal places.

>  > There's no support for line numbers. I haven't seen a need for
>>  anything like that.
>
>
>I always thought it would be nice for my users to scream at me
>and then tell me where the problem is.  :)  A unique ID for each
>(static) message would be almost as good.

It's useful with asserts, but I can't think of anyplace where I've 
used logging where it would be helpful.

>Gotcha.  I like that messages can go to multiple sinks.
>
>>>  From your usage in the previous message, it looks like each
>>>variable in the message is passed as a separate parameter.  Doesn't
>>>that require a whole lot of overloaded methods?
>>
>>  Currently I support LOG functions with up to 10 custom arguments so I
>>  have just over 10 overloaded functions. (Actually I have another 10
>>  because there's a debug only version called TRACE).
>
>
>This seems excessive to me.  It's certainly not scalable.  But maybe
>log messages are short enough that it doesn't matter.

I've gotten up to eight or nine arguments so ten is probably a bit 
too small. OTOH if someone is using LOG with too many arguments they 
could just call LOG more than once...

>  >>Of course the presents the (probably likely) chance that the programmer
>>>will mis-type the category in some message and never see it (since he
>>>doesn't know the name of the category to turn on).  Though inn a
>>>GUI he will at least get some strange menu entries.  :)
>>
>>  Yep, and it is pretty obvious in a GUI app. In other apps I think
>>  you'd still want to do something similar. For example, in the past
>>  I've had app's that wrote the categories to an XML file on shutdown
>>  and read from that file on startup. This way everyone on the team
>>  could easily customize the logging output for the stuff they were
>>  interested in. This isn't as in your face as a menu, but I think
>>  misspelled categories would still be found fairly quickly.
>
>You're probably right, but I'm a fail-fast kinda guy.  :)

Me too, but there are nice advantages to using strings and the 
failure consequences are pretty mild.

   -- Jesse