Re: [boost] Re: logging lib, v1.3

From: John Torjo (john.lists_at_[hidden])
Date: 2004-10-29 05:01:03

>>
>> There is an option for avoiding if() checks in client code at all. All 
>> you have to do is to implement operator<< for logger class.
>>
>> [...]
>>
>> And then in client code:
>>
>>    logger("app.gui") << "something GUIsh";
>>
>> Though I am not sure, if a compiler will be able to optimize checks 
>> for every operator<<() to a single check for the entire output 
>> expression.
> 
> 
> Now replace "something GUIsh" with anExpensiveFunction(). John's code 
> will not evaluate it when the logger is disabled. OTOH your code will 
> always evaluate it, which is IMHO not acceptable for a logging library.
> 
Yes, that's what I want to avoid. Thanks Daniel.

Best,
John

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