iPhone - encoding and decoding a NSValue

Question

So I read here on SO that I can encode a CGLayerRef to a NSValue using

NSValue *myCopy = [[NSValue alloc] initWithBytes:&myLayer objCType:@encode(CGLayerRef)]; 

but how do I recreate the CGLayerRef from myCopy?

thanks

Castora

Answer 1

This should work:

CGLayerRef giveMeBackTheLayer;
[myCopy getValue:&giveMeBackTheLayer];

Pule

just a bit off topic... do you know how can I discover the number of bytes myCopy is using?... thanks. – Castora

@Digital The number of bytes in the whole instance or the number of bytes needed to store a CGLayerRef? It’s probably a combination of class_getInstanceSize() and sizeof CGLayerRef. The actual layer struct is opaque, though. – Pule

You'd need to store that information separately. You can't get it from the NSValue. – April

@Bavarious - the number of bytes needed to store CGLayerRef – Castora

@Digi sizeof CGLayerRef, then. Note that CGLayerRef is a pointer, so it has the same size as any other pointer in your target platform: 32 bits. – Pule