TalkChess.com

[Daniel Shawul]

Agreed. Some more reasons why you may want to have a custom printf :

-different outputs to gui and log file. Some protocols will not work if you print everything to the gui (winboard needs # for comments f.i, others may simply break down)
-stylized printing with headers [processor 0] or [time 3434] , coloring as you mentioned, or simply skipping some prints for a better formatted output etc..
-printing to a socket to another process or a remote machine following a certain protocol as in the case of ICS etc..
-thread safe printing

This can all be wrapped in a cutstom stream class that can be passed around if that simplifies the design of the program. I have even seen information exchange between processors to do parallel processing through an overloaded ">>" operator. Took me some time to figure that out... For chess, it is probably wise to think about this carefully if you are designing a GUI IMO.
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