objective c - xcode UTF-8 literals

Question

Suppose I have the MUSICAL SYMBOL G CLEF symbol: ** ?? ** that I wish to have in a string literal in my Objective-C source file.

The OS X Character Viewer says that the CLEF is UTF8 F0 9D 84 9E and Unicode 1D11E(D834+DD1E) in their terms.

After some futzing around, and using the ICU UNICODE Demonstration Page, I did get the following code to work:

NSString *uni=@"U0001d11e";
NSString *uni2=[[NSString alloc] initWithUTF8String:"xF0x9Dx84x9E"];
NSString *uni3=@"??";
NSLog(@"unicode: %@ and %@ and %@",uni, uni2, uni3);

My questions:

1. Is it possible to streamline the way I am doing UTF-8 literals? That seems kludgy to me.
2. Is the @"U0001d11e part UTF-32?
3. Why does cutting and pasting the CLEF from Character Viewer actually work? I thought Objective-C files had to be UTF-8?

Answer 1

1. I would prefer the way you did it in uni3, but sadly that is not recommended. Failing that, I would prefer the method in uni to that in uni2. Another option would be [NSString stringWithFormat:@"%C", 0x1d11e].
2. It is a "universal character name", introduced in C99 (section 6.4.3) and imported into Objective-C as of OS X 10.5. Technically this doesn't have to give you UTF-8 (it's up to the compiler), but in practice UTF-8 is probably what you'll get.
3. The encoding of the source code file is probably UTF-8, matching what the runtime expects, so everything happens to work. It's also possible the source file is UTF-16 or UTF-32 and the compiler is doing the Right Thing when compiling it. None the less, Apple does not recommend this.