🚀 go-pugleaf

In article <41vst0$9nb@gap.cco.caltech.edu>,
<lemahieu@paradise.caltech.edu> wrote:
> I was under the impression that cout and cin for I/O was actually _faster_
> than using printf.  I thought this was because printf must parse
> the format string each time to determine how the subsequent parameters
> are to be interpreted and output, whereas this is done at compile time
> for cout.  The format string is typically constant but must be reparsed every
> time the printf function is called, which doesn't sound very efficient to me.
> What is the logical argument for printf being faster?
> 
> If anyone has any numbers on stream I/O vs printf, I'd be interested in
> hearing them.

Although I haven't timed cout vs printf.  I have timed similarly
implemented functions based on printf and cout.  If your string has a LOT
of variables, then printf *may* be faster, because the overhead in calling
the '<<' operators for each variable.  However, most of the time, the
cout-type implementation was generally faster.

In my case, the cout-type routines were about 30% faster than the
printf-type.  These strings usually had 2 variables and strlen was usually
about 40 characters.  Of course, longer contiguous strings with fewer
variables performed best.  

My printf-type routine didn't have too many variable types to check for, I
would guess that if it had many variable types to sort through, cout's
performance would be superior (since the function call is decided at
compile time).

-- 
Tom Gooding
tgooding@iastate.edu
Computer Engineering 4