github.com/afumu/libc@v0.0.6/musl/src/ctype/wcwidth.c (about)

     1  #include <wchar.h>
     2  
     3  static const unsigned char table[] = {
     4  #include "nonspacing.h"
     5  };
     6  
     7  static const unsigned char wtable[] = {
     8  #include "wide.h"
     9  };
    10  
    11  int wcwidth(wchar_t wc)
    12  {
    13  	if (wc < 0xffU)
    14  		return (wc+1 & 0x7f) >= 0x21 ? 1 : wc ? -1 : 0;
    15  	if ((wc & 0xfffeffffU) < 0xfffe) {
    16  		if ((table[table[wc>>8]*32+((wc&255)>>3)]>>(wc&7))&1)
    17  			return 0;
    18  		if ((wtable[wtable[wc>>8]*32+((wc&255)>>3)]>>(wc&7))&1)
    19  			return 2;
    20  		return 1;
    21  	}
    22  	if ((wc & 0xfffe) == 0xfffe)
    23  		return -1;
    24  	if (wc-0x20000U < 0x20000)
    25  		return 2;
    26  	if (wc == 0xe0001 || wc-0xe0020U < 0x5f || wc-0xe0100U < 0xef)
    27  		return 0;
    28  	return 1;
    29  }