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</head><body bgcolor="#FFFFFF" text="#000000">Thanks for the pointers.
Good reading, but I'm still confused. I think that the first issue is
clear to me now, but I don't know what I have to do to make the closure
be seen as satisfying the type of the function pointer. It worked in
Swift 2.2 as<br>
<br>
XML_SetEndElementHandler(parser) { (userData:
UnsafeMutablePointer<Void>, name: UnsafePointer<XML_Char>)
-> Void in<br>
<br>
<span>
</span>All that's changed is making the UnsafeMutablePointer<Void>
into UnsafeMutableRawPointer, unless it's the unwrapped nature of the
parameter in the error message:<br>
<br>
Cannot convert value of type '(UnsafeMutableRawPointer,
UnsafePointer<XML_Char>) -> Void' to expected argument type
'XML_EndElementHandler!'
<br>
<br>
I don't know what I need to do next. Any help is much appreciated.<br>
<blockquote style="border: 0px none;"
cite="mid:63E963C6-70EB-4F57-9A2B-8FFFE856FAB4@apple.com" type="cite">
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:2px solid #EDF1F4;padding-top:10px;"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:swift-users@swift.org"
style="color:#485664
!important;padding-right:6px;font-weight:500;text-decoration:none
!important;">Quinn "The Eskimo!" via swift-users</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#909AA4"><span style="padding-left:6px">28
September 2016 at 11:26</span></font></div> </div></div>
<div style="color:#909AA4;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody"><div><!----><br>I recommend
reading the whole “Migrating to Swift 2.3 or Swift 3 from Swift 2.2”
doc, but for this specific issue you should start with the
“UnsafeRawPointer Migration” doc that it links to.<br><br><a class="moz-txt-link-rfc2396E" href="https://swift.org/migration-guide/"><https://swift.org/migration-guide/></a><br><br><a class="moz-txt-link-rfc2396E" href="https://swift.org/migration-guide/se-0107-migrate.html"><https://swift.org/migration-guide/se-0107-migrate.html></a><br><br>Share
and Enjoy<br>--<br>Quinn "The Eskimo!"
<a class="moz-txt-link-rfc2396E" href="http://www.apple.com/developer/"><http://www.apple.com/developer/></a><br>Apple Developer Relations,
Developer Technical Support, Core OS/Hardware<br><br><br>_______________________________________________<br>swift-users
mailing list<br><a class="moz-txt-link-abbreviated" href="mailto:swift-users@swift.org">swift-users@swift.org</a><br><a class="moz-txt-link-freetext" href="https://lists.swift.org/mailman/listinfo/swift-users">https://lists.swift.org/mailman/listinfo/swift-users</a><br></div></div>
<div style="margin:30px 25px 10px 25px;" class="__pbConvHr"><div
style="width:100%;border-top:2px solid #EDF1F4;padding-top:10px;"> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:49%;">
<a moz-do-not-send="true" href="mailto:john_brownie@sil.org"
style="color:#485664
!important;padding-right:6px;font-weight:500;text-decoration:none
!important;">John Brownie</a></div> <div
style="display:inline-block;white-space:nowrap;vertical-align:middle;width:48%;text-align:
right;"> <font color="#909AA4"><span style="padding-left:6px">28
September 2016 at 9:29</span></font></div> </div></div>
<div style="color:#909AA4;margin-left:24px;margin-right:24px;"
__pbrmquotes="true" class="__pbConvBody">I have a Swift wrapper for the
expat XML parser, and I just went through
the update to Swift 3, and I'm thrown a series of errors that mostly
appear to be of two types. Here is a representative function of the
first type:
<br>
<br> func parse() throws {
<br> var done = false
<br> while !done {
<br> let buffer: UnsafeMutablePointer<Void> =
XML_GetBuffer(parser, Int32(bufsize))
<br> if buffer == nil {
<br> let errorCode = XML_GetErrorCode(parser)
<br> throw ExpatError(reason: "Error \(errorCode),
\(XML_ErrorString(errorCode))")
<br> }
<br> let bytesRead =
readData(UnsafeMutablePointer<UInt8>(buffer), bufferLength:
bufsize)
<br> done = bytesRead < bufsize
<br> if XML_ParseBuffer(parser, Int32(bytesRead), Int32(done ?
1
: 0)) != XML_STATUS_OK {
<br> let errorCode = XML_GetErrorCode(parser)
<br> throw ExpatError(reason: "Error \(errorCode),
\(XML_ErrorString(errorCode))")
<br> }
<br> }
<br> }
<br>
<br>Xcode 8's migrator changed the declaration of buffer to
UnsafeMutableRawPointer?, but the readData call gives an error:
<br>
<br>Cannot invoke initializer for type
'UnsafeMutablePointer<UInt8>' with an
argument list of type '(UnsafeMutableRawPointer?)'
<br>Pointer conversion restricted: use '.assumingMemoryBound(to:)' or
'.bindMemory(to:capacity:)' to view memory as a type.
<br>Overloads for 'UnsafeMutablePointer<UInt8>' exist with these
partially
matching parameter lists: (RawPointer), (OpaquePointer),
(OpaquePointer?), (UnsafeMutablePointer<Pointee>),
(UnsafeMutablePointer<Pointee>?)
<br>
<br>Where can I read up on how to make the conversion? My initial effort
is:
<br>
<br> let bytesRead = readData(buffer!.bindMemory(to:
UInt8.self,
capacity: bufsize), bufferLength: bufsize)
<br>
<br>That's more or less thrashing around with no real understanding.
<br>
<br>The second type is turning a closure into the appropriate C function
pointer. For example:
<br>
<br> XML_SetEndElementHandler(parser) { (userData:
UnsafeMutableRawPointer, name: UnsafePointer<XML_Char>) -> Void
in
<br> let theParser = unsafeBitCast(userData, to:
ExpatSwift.self)
<br> let theName = ExpatSwift.getString(name)
<br> theParser.endElement(theName)
<br> }
<br>
<br>This gets an error:
<br>
<br>Cannot convert value of type '(UnsafeMutableRawPointer,
UnsafePointer<XML_Char>) -> Void' to expected argument type
'XML_EndElementHandler!'
<br>
<br>XML_EndElementHandler is defined as:
<br>
<br>typedef void (XMLCALL *XML_EndElementHandler) (void *userData,
<br> const XML_Char
*name);
<br>
<br>Here I have no real clue as to how to fix it.
<br>
<br>So, any pointers to either how to fix these problems or to a good
source
to read to understand them?
<br>
<br>John
<br></div>
</blockquote>
<br>
<div class="moz-signature">-- <br>John Brownie<br>
In Finland on furlough from SIL Papua New Guinea<br>
</div>
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