Re: Determining the length of an objCType

[Richard Frith-Macdonald]

On Monday, December 9, 2002, at 07:00  pm, Andreas Hoeschler wrote:

> Hi all,
>
> I need to encode NSValue on my own (in a category of NSValue). The 
> primitives of NSValue are:
>
> - (const char *)objCType
> - (void)getValue:(void *)buffer
>
> I would like to do something like
>
>    const char *objCType = [self objCType];
>    int length = sizeof(objCType); // <-----------
>    void *buffer = malloc(length);
>    [self getValue:buffer];
>    [archiver encodeString:[NSString stringWithCString:objCType] 
> withName:@"type"];
>    [archiver encodeData:[NSData dataWithBytes:buffer length:length] 
> withName:@"value"];
>    free(buffer);
>
> The marked line of course is incorrect. But how can I get the 
> necessary buffer size from an objC type?

The gnu runtime uses objc_sizeof_type()

eg.

unsigned int size = objc_sizeof_type(@encode(myStructType));