<div dir="ltr">I&#39;ve been working on <a href="https://bugs.swift.org/browse/SR-276" target="_blank">SR-276</a> and I&#39;m finding a fair amount of inconsistencies between corelib Foundation and OS X Foundation. It seems to be most common with optionality of return values. e.g., in NSURL<div><br></div><div>corelib:</div><div>    <span>public</span><span> </span><span>func</span><span> URLByAppendingPathComponent(pathComponent: </span><span>String</span><span>) -&gt; </span><span>NSURL</span><span>?</span></div><div><span><br></span></div><div><span>OS X:</span></div><div><span>    </span><span>public</span><span> </span><span>func</span><span> URLByAppendingPathComponent(pathComponent: </span><span>String</span><span>) -&gt; </span><span>NSURL</span></div><div><span><br></span></div><div>That particular case seems to be a difference in the treatment of the return value from CFURL</div><div><br></div><div>   <span>public</span><span> </span><span>func</span><span> CFURLCreateCopyAppendingPathComponent(allocator: </span><span>CFAllocator</span><span>!, </span><span>_</span><span> url: </span><span>CFURL</span><span>!, </span><span>_</span><span> pathComponent: </span><span>CFString</span><span>!, </span><span>_</span><span> isDirectory: </span><span>Bool</span><span>) -&gt; </span><span>CFURL</span><span>!</span></div><div><span><br></span></div><div><span>Which briefly looking appears to be the same between corelib and OS X.</span></div><div><span><br></span></div><div><span>I&#39;m not sure what the best way forward on these things is, though, as the corelib versions have seemed consistently improved, but presumably we still want maintain compatibility. Anyone have ideas?</span></div>























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