overload op requires stringify overload ??

Bloodnok has asked for the wisdom of the Perl Monks concerning the following question:

Given an attempt to use overload... e.g.

use overload <op> => \&pkg::sub;
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where <op> is one of either '==' or '@{}' and pkg::sub is an existant fully qualified sub, it seems that, whenever I run the test harness (using Test::More), the following error ensues ...

Operation """": no method found, argument in overloaded package
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The only way to avoid it [this error], that I've discovered thus far, is to overload the stringify operator '""' for the package.

Question is, since overload makes no mention of this [feature] that I can discern, has any one else encountered this problem... and if so, how was the problem resolved ??

Update:

As well as actually overloading the stringify operator, changing :

use overload <op> => \&pkg::sub;
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to read :

use overload <op> => \&pkg::sub, fallback => 1;
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appears to provide a fix of sorts...

A user level that continues to overstate my experience :-))

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Re: overload op requires stringify overload ?? by lostjimmy (Chaplain) on Feb 17, 2009 at 19:18 UTC
I believe this is the expected behavior. If you are overloading, you have to provide all of the overloads, otherwise Perl will complain. For instance, if you only overload '==' and then try to use the '+' operator, you get the `Operation "+": no method found`. Using fallbacks, Perl will try to figure out what you want to do for certain overloads, of which stringification is one of them. Update: The minimal set of overloaded operations may be helpful.	[reply] [d/l]

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Re: overload op requires stringify overload ??
by lostjimmy (Chaplain) on Feb 17, 2009 at 19:18 UTC

I believe this is the expected behavior. If you are overloading, you have to provide all of the overloads, otherwise Perl will complain. For instance, if you only overload '==' and then try to use the '+' operator, you get the Operation "+": no method found. Using fallbacks, Perl will try to figure out what you want to do for certain overloads, of which stringification is one of them.

Update: The minimal set of overloaded operations may be helpful.

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