/* https://git.datadissipation.net */
#ifndef ASPRINTF_H_
 #define ASPRINTF_H_ 1

 #ifdef ASPRINTF_INCLUDE_LIBC_
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
 #endif

 #ifndef HAVE_ASPRINTF
  int vasprintf_(char **strp, const char *fmt, va_list ap);
  int asprintf_(char **strp, const char *fmt, ...);
  /* 
   * Credit for a big part of the macro madness:
   * Jens Gustedt
   * https://gustedt.wordpress.com/2010/06/08/detect-empty-macro-arguments/
   */
  #define vasprintf(s, f, a)   vasprintf_(s, f, a)
  #define I_COND_COMMA_(...) ,
  #define I_PICK_ARG_(_1, _2, ARG, ...) ARG
  #define I_HAS_COMMA_(...) I_PICK_ARG_(__VA_ARGS__, 1, 0)
 
  #define I_ISEMPTY_(...)                                                      \
  II_ISEMPTY_(                                                                 \
	  /* test if there is just one argument, eventually an empty           \
	  one */                                                               \
	  I_HAS_COMMA_(__VA_ARGS__),                                           \
	  /* test if I_COND_COMMA_ together with the argument                  \
	  adds a comma */                                                      \
	  I_HAS_COMMA_(I_COND_COMMA_ __VA_ARGS__),                             \
	  /* test if the argument together with a parenthesis                  \
	  adds a comma */                                                      \
	  I_HAS_COMMA_(__VA_ARGS__ (/*empty*/)),                               \
	  /* test if placing it between I_COND_COMMA_ and the                  \
	  parenthesis adds a comma */                                          \
	  I_HAS_COMMA_(I_COND_COMMA_ __VA_ARGS__ (/*empty*/))                  \
	  )
 
  #define I_PASTE5_(_0, _1, _2, _3, _4) _0 ## _1 ## _2 ## _3 ## _4
  #define II_ISEMPTY_(_0, _1, _2, _3)\
  I_HAS_COMMA_(I_PASTE5_(I_IS_EMPTY_CASE_, _0, _1, _2, _3))
  #define I_IS_EMPTY_CASE_0001 ,

  #define II_PASTE_(a) I_EMPTY_##a
  #define I_PASTE_(a) II_PASTE_(a)

  #define I_GET_ARG_(...) I_PICK_ARG_(__VA_ARGS__)
  #define asprintf(s, f, ...)\
  asprintf_(s, f I_PASTE_(I_ISEMPTY_(I_GET_ARG_(, , __VA_ARGS__))) __VA_ARGS__)
  #define I_EMPTY_1
  #define I_EMPTY_0 I_COND_COMMA_()
 #endif

 #ifdef ASPRINTF_IMPLEMENTATION_
 int
 vasprintf_(char **strp, const char *fmt, va_list ap)
 {
 	 int size, ret;
 	 va_list tp;

	 va_copy(tp, ap);
	 size = vsnprintf(NULL, 0, fmt, tp);
	 va_end(tp);

	 if (size < 0) {
		 return -1;
	 }
	 *strp = malloc(size + 1);
	 if (*strp == NULL) {
		 return -1;
	 }

	 ret = vsnprintf(*strp, size + 1, fmt, ap);
	 if (ret < 0) {
		 free(*strp);
		 return -1;
	 }

	 return ret;
 }

 int
 asprintf_(char **strp, const char *fmt, ...)
 {
	 int ret;
	 va_list ap;

	 va_start(ap, fmt);
	 ret = vasprintf(strp, fmt, ap);
	 va_end(ap);

	 return ret;
 }
 #endif
#endif