Thanks Jeremy & Ole, That was indeed my expectation, but I had not thought of looking in the source code!
Regards, Rien Site: http://balancingrock.nl Blog: http://swiftrien.blogspot.com Github: http://github.com/Swiftrien Project: http://swiftfire.nl > On 03 Jan 2017, at 16:31, Ole Begemann <o...@oleb.net> wrote: > >> What I cannot find though is the guarantee that the buffer where the >> String is converted to an UTF8 sequence is always null-terminated. >> >> I very much suspect it is, and all my tests did find a null-terminated >> string. >> >> Question: Does anybody know for sure that the buffer is always >> null-terminated? (a link to where I can check this would be most >> appreciated) > > I'm not 100% certain, but I think the compiler uses this function to convert > a String argument to a pointer: > > /// Derive a UTF-8 pointer argument from a value string parameter. > public // COMPILER_INTRINSIC > func _convertConstStringToUTF8PointerArgument< > ToPointer : _Pointer > >(_ str: String) -> (AnyObject?, ToPointer) { > let utf8 = Array(str.utf8CString) > return _convertConstArrayToPointerArgument(utf8) > } > > Source: Pointer.swift [1] > > This in turn calls `String.utf8CString` [2], which indeed returns a > null-terminated string. > > [1]: > https://github.com/apple/swift/blob/master/stdlib/public/core/Pointer.swift#L85-L92 > [2]: > https://github.com/apple/swift/blob/master/stdlib/public/core/StringUTF8.swift#L383-L405 > _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
