You'll have to explain how, then. The caller can't know that an array was involved because the caller only gets a list of scalar values pushed onto the stack.

I gave you examples of difference between returning array and list. For example, "return @ab" is not the same as "return (@ab, 'txt')". In the first case assignment of returned value to scalar will produce the count of elements in the array. In the second case it will produce the 'txt'. You can try "return ('txt', @ab)" and again you'll get count of elements in @ab when assigning to scalar. So the caller gets not the list of scalar values, but the list of objects, some of which may be hashes or arrays and some scalars.

The copying magic happens when transferring objects from stack into the destination. The destination gets the copy of what was on the stack, but the copy might be flattened. So, if the list of scalars is needed, then the arrays and hashes will be expanded. But if the single scalar is needed, then the last object from the stack will be taken and "converted" into scalar.

Half of the code proves that the 'for' loop gets copies. The other half of the code proves that 'for' loops don't get copies when using an array. That's one of the major features of 'for' loops: They work on aliases not copies when possible. When calling a function, working on aliases isn't possible (because what gets pushed onto the stack is copies of each scalar value).

This is only because the values from the stack are copied into the list and only after that "for" has a chance to alias them. If you use the array directly, then the values are not copied (there's no stack involved). So the "for" loop has chance to alias the elements of the array directly. Remember the rule. Returned on the stack values are always copied before they can be used!

In reply to Re^6: Confused as to why the "casting context" is mis-behaving (return array) by andal
in thread Confused as to why the "casting context" is mis-behaving by kiz

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