Re: Unchecked_Deallocation subtleties

[Samuel Tardieu <sam@rfc1149.net>]

>>>>> "Nick" == Nick Roberts <nickroberts@blueyonder.co.uk> writes:

Nick> Consider the following example skeleton piece of code:

Nick>    declare
Nick>       X: Some_Access_Type;
Nick>    begin
Nick>       ...  -- [1] Y := X.all; -- [2] last use of X ...  -- [3]
Nick>       Free(X); -- [4]
Nick>    end;

Nick> Although it may be that no compiler would (or even could) do so
Nick> in practice, other rules in the ARM made it theoretically
Nick> possible for the implementation to automatically reclaim the
Nick> storage occupied by whatever X pointed to (assuming no other
Nick> access value pointed to it) at any point in the elided code
Nick> section [3].

I would say that Free(X) is certainly a use of X, so the last use of X
is not in [2], it is in [4].

  Sam
-- 
Samuel Tardieu -- sam@rfc1149.net -- http://www.rfc1149.net/sam