Thank Joe, A first attempt was not successful, I will try again in a few days.
For now I have put in a work around where I put glue-code into the openSSL library itself. I don’t like that solution, but it works. Regards, Rien Site: http://balancingrock.nl Blog: http://swiftrien.blogspot.com Github: http://github.com/Balancingrock Project: http://swiftfire.nl > On 25 Jan 2017, at 19:37, Joe Groff <jgr...@apple.com> wrote: > > >> On Jan 25, 2017, at 1:23 AM, Rien via swift-users <swift-users@swift.org> >> wrote: >> >> I have a case where a callback has the following signature: >> >> @convention(c) (_ ssl: OpaquePointer?, _ num: UnsafeMutablePointer<Int32>?, >> _ arg: UnsafeMutableRawPointer?) -> Int32 >> >> But to install this callback I have to use a c-function with this signature: >> >> SSL_CTX_callback_ctrl (OpaquePointer!, Int32, (() -> Void)! ) >> >> Is it possible to cast the first function to the second? If so, how? > > I think your best bet would be to write the shim closure yourself. Is `num` a > pointer to the value you're supposed to receive from SSL_CTX_callback_ctrl? > Is the `arg` really a function pointer? In that case, something like this > might work: > > func callback(_ ssl: OpaquePointer?, _ num: UnsafeMutablePointer<Int32>?, _ > arg: UnsafeMutableRawPointer?) -> Int32 > > let shimCallback: SSL_CTX_callback_ctrl = { ctx, cmd, fp in > var cmdNum = cmd > callback(ctx, &cmdNum, unsafeBitCast(fp, to: UnsafeMutableRawPointer?.self)) > } > > -Joe _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
