Hi Thorsten,
On Wed, Mar 19, 2025 at 04:56:32PM +0100, Thorsten Glaser wrote:
> On Tue, 18 Mar 2025, Alejandro Colomar wrote:
>
> >> To address this adoption problem, how about changing these function to
> >> generic functions (in the sense of <tgmath.h>)? In such a way that
> >> strtoi (n, &end, base, LONG_MIN, LONG_MAX, &status)
> >> is known to return a 'long' rather than 'intmax_t', and
> >> strtoi (n, &end, base, INT_MIN, INT_MAX, &status)
>
> That, and especially…
Please propose an implementation of the overload-selectinging macro, and
clarify how this should work:
n = strto*(s, NULL, 0, SHRT_MIN, UINT_MAX, &status);
Do we use typeof(min + max)? Which is the type to use?
Also, aren't you worried about going inventive in the standard? I feel
safer with this old API than one invented now.
> >I have designed a better API, through a type-generic macro:
> >
> > int
> > a2i(typename T, T *restrict n, QChar *s,
> > QChar *_Optional *restrict endp, int base,
> > T min, T max);
> […]
>
> … this is a nightmare. This effectively will prevent people from
> adding that to systems that do not use C2y as primary/only target
> yet, and mixing code.
That macro can be implemented with C11. Here's the implementation I
wrote for shadow-utils, which we've been using and distributing for a
year already:
#define a2i(TYPE, n, s, ...) \
( \
_Generic((void (*)(TYPE, typeof(s))) 0, \
void (*)(short, const char *): a2sh_c, \
void (*)(short, const void *): a2sh_c, \
void (*)(short, char *): a2sh_nc, \
void (*)(short, void *): a2sh_nc, \
void (*)(int, const char *): a2si_c, \
void (*)(int, const void *): a2si_c, \
void (*)(int, char *): a2si_nc, \
void (*)(int, void *): a2si_nc, \
void (*)(long, const char *): a2sl_c, \
void (*)(long, const void *): a2sl_c, \
void (*)(long, char *): a2sl_nc, \
void (*)(long, void *): a2sl_nc, \
void (*)(long long, const char *): a2sll_c, \
void (*)(long long, const void *): a2sll_c, \
void (*)(long long, char *): a2sll_nc, \
void (*)(long long, void *): a2sll_nc, \
void (*)(unsigned short, const char *): a2uh_c, \
void (*)(unsigned short, const void *): a2uh_c, \
void (*)(unsigned short, char *): a2uh_nc, \
void (*)(unsigned short, void *): a2uh_nc, \
void (*)(unsigned int, const char *): a2ui_c, \
void (*)(unsigned int, const void *): a2ui_c, \
void (*)(unsigned int, char *): a2ui_nc, \
void (*)(unsigned int, void *): a2ui_nc, \
void (*)(unsigned long, const char *): a2ul_c, \
void (*)(unsigned long, const void *): a2ul_c, \
void (*)(unsigned long, char *): a2ul_nc, \
void (*)(unsigned long, void *): a2ul_nc, \
void (*)(unsigned long long, const char *): a2ull_c, \
void (*)(unsigned long long, const void *): a2ull_c, \
void (*)(unsigned long long, char *): a2ull_nc, \
void (*)(unsigned long long, void *): a2ull_nc \
)(n, s, __VA_ARGS__) \
)
And here's the definition of one of the overloads:
int
a2sl_nc(long *restrict n, char *s,
char **restrict endp, int base, long min, long max)
{
int status;
*n = strtoi(s, endp, base, min, max, &status);
if (status != 0) {
errno = status;
return -1;
}
return 0;
}
> (Besides, a2i is a too generic name.)
I named it like atoi(3), just replacing s/to/2/. It is just as generic
as the name of the APIs it intends to supersede.
> bye,
> //mirabilos
> PS: Please don’t Cc me explicitly on this thread.
Ok. Have a lovely day!
Alex
--
<https://www.alejandro-colomar.es/>
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