Submission Date: 10 Dec 92
Source: X3J11/91-061 (Vania Joloboff)
My interpretation of the Standard is that the value of MB_CUR_MAX must be one in the "C" locale. I infer that from the fact that:
However this clarification should be made explicit.
In fact 3, we presume the second sentence was intended to be: ``A character constant is regarded as having type char,'' in order to be applicable to this request. That is not true; a character constant is of type int. Also facts 1-4 deal with the single-byte chars and not the extended character set.
In any case, the facts as listed do not logically lead to the conclusion that MB_CUR_MAX must be one (1) in the "C" locale. In fact, this conclusion is not true. It is possible for MB_CUR_MAX to be greater than one in the "C" locale. In subclause 7.10, page 149, MB_CUR_MAX is ``the maximum number of bytes in a multibyte character for the extended character set specified by the current locale.'' In subclause 184.108.40.206, page 107, the "C" locale is ``the minimal environment for C translation.'' The minimal environment may still require more than one byte for multibyte characters.
I also would like to make a requirement that if the current locale is the "C" locale, the value returned by setlocale(LC_ALL, NULL) be a string of length one, consisting of the single character C.
Currently the value of setlocale(LC_ALL, NULL) is unspecified for the "C" locale.
This makes it difficult to build libraries where you want to maintain the behavior pre-existing to internationalization for backward compatibility.
Typically you want to say in these programs:
if (*setlocale(LC_ALL, NULL) == 'C')
do the old thing
do the new thing
The reference is to subclause 220.127.116.11, page 107.
The Committee acknowledges that there exists no strictly portable method for determining whether the current locale is the "C" locale. The request for this feature is neither an erratum nor a request for interpretation; it is a request for an amendment. The Committee will consider this request for a future revision of the C Standard.