On Thursday, 3 January 2013 at 22:50:38 UTC, Rob T wrote:
On Thursday, 3 January 2013 at 21:56:22 UTC, David Nadlinger
wrote:
I must admit that I haven't read the rest of the thread yet,
but I think the obvious and correct solution is to disallow
passing locals (including non-ref parameters, which are
effectively locals in D) as non-scope ref arguments.
The problem with that idea, is that a ref return with no
arguments may call another ref return that returns something
that escapes the scope it was created in. If the source code is
not available, then there's no way for the compiler to
determine that this is going on.
I am not quite sure what you are trying to say. If the compiler
never sees the source code for the functions, then codegen is
going to be difficult. ;)
Yes, if you just see "void iPromiseNotToEscapeMyParameter(scope
ref int a) @safe;", then there is no way to directly check that
the function actually does not leak the parameter address.
However, you can be sure that the compiler checked that when
generating the code for the function.
David
