I used both OC and Swift in my current project. The mixed code works fine in Xcode 6 beta. Currently, when I update Xcode 6 beta to beta 5. Then I came across many compile errors most of which are mainly caused by the new features of Swift language itself. I fixed all the syntax-related bugs remaining one compile error which is:
"Swift is unavailable on iOS earlier than 7.0; please set IPHONEOS_DEPLOYMENT_TARGET to 7.0 or later (currently it is '4.3')"
When I changed the deployment target to 7.0 and compile the project, new compile errors occurred:
"Use of undeclared identifier 'char32_t'"
This compile error appears in the file /Applications/Xcode6-Beta5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1.