NAME

nan, nanf, nanl - return quiet NaN

LIBRARY

Math Library (libm, -lm)

SYNOPSIS



double nan(const char *tagp)

float nanf(const char *tagp)

long double nanl(const char *tagp)

DESCRIPTION

The call nan("n-char-sequence") is equivalent to the call strod("NAN(n-char-sequence)", NULL). The call nan("") is equivalent to the call strod("NAN()", NULL).

The nanf() and nanl() functions are equivalent to nan() but substituting strtof() and strtod(), respectively.

RETURN VALUES

IEEE 754

The nan(), nanf(), and nanl() functions return a quiet NaN as specified by tagp.

VAX

The nan(), nanf(), and nanl() functions return zero.

SEE ALSO

math(3), strod(3)

STANDARDS

The nan(), nanf(), and nanl() functions conform to ISO/IEC 9899:1999 (``ISO C99'') .