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/***********************************************************************
nan, nanf, nanl - return quiet NaN
These functions shall return a quiet NaN, if available, with content
indicated through tagp.
If the implementation does not support quiet NaNs, these functions
shall return zero.
Calls: strlen(), sprintf(), strtod()
***********************************************************************/
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
double nan (const char *tagp)
{
if (tagp[0] != '\0') {
char buf[6 + strlen (tagp)];
sprintf (buf, "NAN(%s)", tagp);
return strtod (buf, NULL);
}
return NAN;
}
float nanf (const char *tagp)
{
if (tagp[0] != '\0') {
char buf[6 + strlen (tagp)];
sprintf (buf, "NAN(%s)", tagp);
return strtof (buf, NULL);
}
return NAN;
}
#if 0
long double nanl (const char *tagp)
{
if (tagp[0] != '\0') {
char buf[6 + strlen (tagp)];
sprintf (buf, "NAN(%s)", tagp);
return strtold (buf, NULL);
}
return NAN;
}
#endif
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