Unexpected performance results

[Dave]

Hello all,

Can anybody think of a plausible explanation for why my profiler is telling
me that I get better performance with map::operator[] than with
map::insert()?

Thanks,
Dave

[Leor Zolman]

Re: Unexpected performance results

On Thu, 8 Apr 2004 11:24:24 -0700, "Dave" <better_cs_now@ yahoo.com> wrote:
[color=blue]
>Hello all,
>
>Can anybody think of a plausible explanation for why my profiler is telling
>me that I get better performance with map::operator[] than with
>map::insert( )?[/color]

This would be totally a QOI issue, but I did take a look just for grins in
an implementation or two, and I noticed that, even though operator[] tends
to call insert() to do its work, insert() returns a pair<...> by value
while operator[] just returns a ref to an element. Perhaps the construction
of that return value from insert() might be your culprit...
-leor[color=blue]
>
>Thanks,
>Dave
>[/color]

--
Leor Zolman --- BD Software --- www.bdsoft.com
On-Site Training in C/C++, Java, Perl and Unix
C++ users: Download BD Software's free STL Error Message Decryptor at:

https://www.bdsoft.com/tools/stlfilt.html

[Leor Zolman]

Re: Unexpected performance results

On Thu, 8 Apr 2004 11:24:24 -0700, "Dave" <better_cs_now@ yahoo.com> wrote:
[color=blue]
>Hello all,
>
>Can anybody think of a plausible explanation for why my profiler is telling
>me that I get better performance with map::operator[] than with
>map::insert( )?[/color]

This would be totally a QOI issue, but I did take a look just for grins in
an implementation or two, and I noticed that, even though operator[] tends
to call insert() to do its work, insert() returns a pair<...> by value
while operator[] just returns a ref to an element. Perhaps the construction
of that return value from insert() might be your culprit...
-leor[color=blue]
>
>Thanks,
>Dave
>[/color]

--
Leor Zolman --- BD Software --- www.bdsoft.com
On-Site Training in C/C++, Java, Perl and Unix
C++ users: Download BD Software's free STL Error Message Decryptor at:

https://www.bdsoft.com/tools/stlfilt.html