ToCString and FromCString and Memory Flushing

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I'm sure I've asked this before and received vague/contradictory replies. Now that FlushMem has been deprecated, what needs to be done with ToCString and FromCString?

I assumed ( apparently wrongly ) that FromCString needed no action and that ToCString needed a MemFree call, but MemFree seems to mess up ( causes subsequent program execution not to occur even though the program doesn't stop ) when used with a Byte Ptr returned from a string's ToCString() method.

Chris C

you need to assign straight away to a max string with FromCString

Perturbatio

You could always manage memory yourself and use GCCollect

Peter Scheutz

You need to free the ToCString().

Read this topic: http://www.blitzbasic.com/Community/posts.php?topic=53269

Hi,

Here's the story:

String.ToCString() and String.ToWString() return pointers that you must manually free yourself using MemFree.

The $Z data type can only be used with function parameters, and automagically handles the ToCString/MemFree stuff for you - it does not actually use GC at all.

The $Z setup assumes that the receiving c function does NOT 'hold onto' or otherwise use the c string after the function returns. In other words, $Z can be thought of as 'const char *'.

I did briefly consider getting rid of $Z altogether (and forcing everyone to use ToCString/MemFree) but realized it would require quite a module overhaul to achieve.

I'll probably add $W at a later date too.

Bye,
Mark Sibly
WinXP, DX9.0b, P4/3G, 512M, Radeon 9800
MacOS10.3, G5/1.8G, 768M, GeForce 6800 Ultra

Gabriel

That's exactly what I was looking for, thanks. I knew I'd seen it somewhere.