easy histogram disabling

Dear ROOTers,

when debugging software, I often come across the issue, that I'd like to make extensive use of histograms to understand some problem in detail, however I'd like to be able to turn off these histograms (because of memory and speed issues) when the same code is used in production.

The obvious solution is to write code along the lines of:

TH3D *h1;
if (debug)

   h1 = new TH3D(...);
else

   h1 = NULL;

...

if (debug1)

   h1->Fill(...);
if (debug2)

   h2->Fill(...);
if (debug3)

   h3->Fill(...);

...

However, this impairs the readability of the code, especially when large numbers of histograms and different levels of debugging are used.

To my mind, there would be a simple way to improve this. Adding to the top of the THxx::Fill() methods

   if (!this) return;

would allow much cleaner code:

h1->Fill(...);
h2->Fill(...);
h3->Fill(...);

What do you think? Would you accept a patch?

Cheers,
Thiemo

-- 
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| Dipl.-Phys. Thiemo Nagel          |                          |

| Technische Universitaet Muenchen  | Room    PH1 3276         |

| Physik-Department E18             |                          |

| James-Franck-Strasse              | Phone  +49 89 289-12379  |

| D-85747 Garching                  | Fax    +49 89 289-12570  |

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