On Thu, Jul 7, 2011 at 22:10, <michael.vancann...@wisa.be> wrote: > Sigh.... > > That's what I've been saying all along. You don't even need strings for it. > Plain records and integers will do it just as well.
Well, I am sorry, but do you all (not only Michael, I'm just responding to the last mail in the thread) really think I am stupid enough to not know it? It is quite understandable that FPC developers want to defend the status quo, but can you please do it by responding to the argument OP and I actually make? I'll re-iterate again: 1) The reference counting is not just an optimization, it is also a memory management technique, an important concept which is aimed at providing "simple value" semantics for heap-allocated structures, and insulating the programmer from memory allocation details. If programmer does not do anything obviously dangerous like direct memory access, using strings is guaranteed not to cause a whole class of memory errors, like leaks, double-frees and access-after-free. Current "const string" implementation breaks this guarantee for the sake of minor optimization. It is actually quite ridiculous: "var s: String" *is now safer* than "const s: String", because the former can not cause AV, but the latter can. 2) Also, there is a separate-but-related issue that Object Pascal traditionally conflates "const" and "reference" semantics in parameters. It would be significantly better to have separate "const" and "constref" attributes, but I guess it is much too late. Nevertheless, currently there are two groups of types in FPC, "simple" types like numerics for which "const" acts like "passing by value", and "complex" types for which "const" acts like "passing by reference". Note that currently "const string" *is passed by value*, *except when the reference count equals to 1*, when it suddenly behaves as if passed by reference. -- Alexander S. Klenin _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
