Re: Possible Memory Leak

[Brian May <bam@snoopy.apana.org.au>]

>>>>> "R" == R A Matthews <ram@noone.nowhere> writes:

    R> This ensures that the target of the assignment is adjusted, so
    R> Self is set correctly and gives the target its own copy of the
    R> referenced data.

    R> BUT the Standard says that the temporary variable need not be
    R> finalized, in which case the temporary's data is not
    R> deallocated and so we have a memory leak.

Noone has responded - strange; I will bite.

I don't claim to be any expert, and I don't claim to completely
understand the problem either, but I suspect you are imagining a
problem where no problem exists.

The compiler will manage allocation and deallocation of temporary
variables, as required for you. If in doubt, either print a message in
each routine and see when it is executed, or look at the assembler
code.

In a previous post, I said:

Arr(1) := Empty expands into:

+ Temp := Empty;        -- shallow copy
+ Finalize(Arr(1));
+ Arr(1) := Temp;       -- shallow copy
+ Adjust(Arr(1));

This could also be written as:

+ Temp := Empty;        -- shallow copy
+ Finalize(Arr(1));
+ Adjust(Temp);
+ Arr(1) := Temp;       -- shallow copy

Where you can see that Temp is adjusted, and not finalised, but no
memory leak occurs either.

(disclaimer: I didn't check if this is what happens, however nobody
accused me of getting it wrong either...).
-- 
Brian May <bam@snoopy.apana.org.au>