Question

Under ARC, is it possible to encode/decode a CGMutablePathRef (or its non-mutable form) using NSCoding? Naively I try:

path = CGPathCreateMutable();
...
[aCoder encodeObject:path]

but I get a friendly error from the compiler:

Automatic Reference Counting Issue: Implicit conversion of an Objective-C pointer to 'CGMutablePathRef' (aka 'struct CGPath *') is disallowed with ARC

What can I do to encode this?

Answer 1

NSCoding is a protocol. Its methods can only be used with objects that conform to the NSCoding protocol. a CGPathRef isn’t even an object, so NSCoding methods won’t work directly. That’s why you’re getting that error.

Here’s a guy who has come up with a way to serialize CGPaths.