I apologize.

is.h

/*
 * is.h
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the
 * License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef IS_H_
#define IS_H_

#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201100L
#error C11 or newer is required
#endif

#include <stddef.h>
#include <stdint.h>
#include <inttypes.h>
#include <sys/types.h>
#include <string.h>

#define ptr_is_(type, x, y) type: ((*((type)(uintptr_t)(x))) == (*((type)(uintptr_t)(y))))
#define chr_is_(type, x, y) type: (((type)(uintptr_t)(x)) == ((type)(uintptr_t)(y)))
#define int_is_(type, x, y) chr_is_(type, x, y), ptr_is_(type *, x, y)
#define cmp_is_(type, cmp, x, y) type: (!cmp((type)(uintptr_t)(x), (type)(uintptr_t)(y)))

#define is(x, y)                                                        \
        (((!(x)) && (!(y))) ||                                          \
         ((x) && (y) &&                                                 \
          _Generic((x),                                                 \
                   chr_is_(char, x, y),                                 \
                                                                        \
                   chr_is_(signed char, x, y),                          \
                   int_is_(signed short int, x, y),                     \
                   int_is_(signed int, x, y),                           \
                   int_is_(signed long int, x, y),                      \
                   int_is_(signed long long int, x, y),                 \
                   int_is_(signed __int128, x, y),                      \
                                                                        \
                   chr_is_(unsigned char, x, y),                        \
                   int_is_(unsigned short int, x, y),                   \
                   int_is_(unsigned int, x, y),                         \
                   int_is_(unsigned long int, x, y),                    \
                   int_is_(unsigned long long int, x, y),               \
                   int_is_(unsigned __int128, x, y),                    \
                                                                        \
                   cmp_is_(unsigned char *, strcmp, x, y),              \
                   cmp_is_(signed char *, strcmp, x, y),                \
                   cmp_is_(char *, strcmp, x, y),                       \
                                                                        \
                   void *: (((intptr_t)(x)) == ((intptr_t)(y)))         \
                  )                                                     \
         )                                                              \
        )

#endif /* !IS_H_ */