>>>>Does anyone know of a way to determine if a variable has been passed to a function by reference or by value. This is a run-time question.
>>>>For example:
>>>>

>>>>local a
>>>>a='test'
>>>>=Test(@a)
>>>>=Test(a)
>>>>
>>>>procedure Text
>>>>lparameter b
>>>>*-- here, i would like to verify that the variable 'a' was passed to 'b' as by reference.
>>>>...
>>>>

>>>
>>>The best you can do is this.
>>>Obviously it's no use.
>>>
>>>

>>>PRIVATE a
>>>a='test'
>>>=Testa(@a)
>>>=Testa(a)
>>>PUBLIC x
>>>=Testx(@x)
>>>=Testx(x)
>>>
>>>procedure Testa
>>>lparameter b
>>>MESSAGEBOX("variable b "+IIF(VARTYPE(m.a)=='U',"Reference to a","is a stand-alone variable"))
>>>
>>>procedure Testx
>>>lparameter b
>>>MESSAGEBOX("variable b "+IIF(VARTYPE(m.x)=='U',"Reference to x","is a stand-alone variable"))
>>>

>>
>>Thanks, I've looked at a simular approach. The problem is that the callee would not know the name of the argument the caller is using.
>
>the bad side effect of this is that on VFP a public ( or private ) variable can disappear
>without a reasonable:
>

>PUBLIC x
>ACTIVATE SCREEN
>sideLevel1()
>
>PROCEDURE sideLevel1(stop)
>	? PROGRAM()
>	? m.x
>	IF m.stop
>		RETURN
>	ENDIF
>	sideLevel2(@m.x)
>	
>PROCEDURE sideLevel2(stop)
>	sideLevel1(.T.)
>

Interesting.