From: tr.17687@z991.linuxsc.com   
      
   Keith Thompson  writes:   
      
   > Thiago Adams  writes:   
   >   
   >> speaking on signed x unsigned,   
   >>   
   >> u8"a"  in C11 had the type char [N]. Normally char is signed   
   >   
   > I would have said "commonly" rather than "normally".  Not an   
   > important point.   
   >   
   >> in C23 it is unsigned char8_t  [N].   
   >>   
   >> when converting code from c11 to c23 we have a error here   
   >> const char* s = u8""   
   >>   
   >>   
   >> I generally "cast char* " to "unsigned char*" when handling   
   >> something with utf8.  I am not u8"" , I use just " " with utf8   
   >> encoded source code and I just assume const char* is utf8.   
   >   
   > That raises another issue.   
   >   
   > The  header was introduced in C99.  In C99, C11, and C17,   
   > that header defines char16_t and char32_t.  C23 introduces char8_t.   
   >   
   > There doesn't seem to be any way, other than checking the value of   
   > __STDC_VERSION__ to determine whether char8_t is defined or not.   
   > There are not *_MIN or *_MAX macros for these types, either in   
   >  or in .  A test program I just wrote would have   
   > been a little simpler if I could have used `#ifdef CHAR8_MAX`.   
   >   
   > Here's the test program :   
   >   
   > #include    
   > #include    
   >   
   > #define TYPEOF(x) \   
   >     (_Generic(x, \   
   >         char:  "char", \   
   >         signed char:  "signed char", \   
   >         unsigned char:  "unsigned char", \   
   >         short:  "short", \   
   >         unsigned short:  "unsigned short", \   
   >         int:  "int", \   
   >         unsigned int:  "unsigned int", \   
   >         long:  "long", \   
   >         unsigned long:  "unsigned long", \   
   >         long long:  "long long", \   
   >         unsigned long long:  "unsigned long long"))   
   >   
   > int main(void) {   
   >     printf("__STDC_VERSION__ = %ldL\n", __STDC_VERSION__);   
   >     printf("u8\"a\"[0] is of type %s\n",   
   >            TYPEOF(u8"a"[0]));   
   > #if __STDC_VERSION__ >= 202311L   
   >     printf("char8_t is %s\n", TYPEOF((char8_t)0));   
   > #endif   
   >     printf("char16_t is %s\n", TYPEOF((char16_t)0));   
   >     printf("char32_t is %s\n", TYPEOF((char32_t)0));   
   > }   
   >   
   > Its output with `gcc -std=c17` :   
   >   
   > __STDC_VERSION__ = 201710L   
   > u8"a"[0] is of type char   
   > char16_t is unsigned short   
   > char32_t is unsigned int   
   >   
   > Its output with `gcc -std=c23` :   
   >   
   > __STDC_VERSION__ = 202311L   
   > u8"a"[0] is of type unsigned char   
   > char8_t is unsigned char   
   > char16_t is unsigned short   
   > char32_t is unsigned int   
      
   Since C23 defines char8_t to be the same type as unsigned char,   
   it seems better to just define it when it isn't there:   
      
       #include    
      
       #if CHAR_BIT == 8 && __STDC_VERSION__ < 202311   
       typedef unsigned char char8_t;   
       #endif   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)