Question

I’m trying to use

NSString *iosString = [[NSString alloc] initWithFormat:@"%ls = %ls" arguments:argListSave];

The problem is that initWithFormat does not support %ls, and argListSave contain wchar_t*, how can I get around this limitation?

Answer 1

wchar_t *ws1 = va_arg(argListSave, wchar_t *);
wchar_t *ws2 = va_arg(argListSave, wchar_t *);

NSString *s1 = [[NSString alloc] initWithCharacters:ws1 length:wstrlen(ws1)];
NSString *s2 = [[NSString alloc] initWithCharacters:ws2 length:wstrlen(ws2)];

NSString *iosString = [[NSString alloc] initWithFormat:@"%@ = %@", s1, s2];
[s1 release];
[s2 release];

Edit: it seems that the two character types are of different size. You may thus want to implement an strcpy-like conversion function like this:

unichar *wchar_to_unichar(unichar *result, wchar_t *input)
{
    while (*input)
    {
        *result++ = *input++;
    }
    return result;
}

Edit 2: seems this is still not good. As @Jonathan Grinspan pointed out, you have to consider UTF32 code points as well and use

initWithBytes:length:encoding:

with NSUTF32LittleEndianStringEncoding on Intel macs and NSUTF32BigEndianStringEncoding on PowerPC Macs (length being thr string length in bytes, not characters).