cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> #include <cvticw.h> extern float cvtidf (const char *s, char **endptr); extern double cvtid (const char *s, char **endptr); extern long double cvtidl (const char *s, char **endptr); extern __float80 cvtidw (const char *s, char **endptr); extern __float128 cvtidq (const char *s, char **endptr); extern long_long_double cvtidll (const char *s, char **endptr); extern decimal_float cvtiddf (const char *s, char **endptr); extern decimal_double cvtidd (const char *s, char **endptr); extern decimal_long_double cvtiddl (const char *s, char **endptr); extern decimal_long_long_double cvtiddll (const char *s, char **endptr);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
3.141593e+00 3.141593 3.141_592_653_589_793_238_462_643_383_279_503 +3.14159_26535_89793_23846_26433_83279_50288E+00000_00000
Exponents of decimal floating-point numbers are decimal values that represent powers of ten.
As illustrated, digits in the significand and/or exponent may be separated by a single underscore for enhanced readability, and lettercase is not significant.
Numbers may contain valid C-style numeric-precision suffixes: f or F (float), l or L (long double), ll or LL (long_long_double), df or DF (decimal_float), dd or DD (decimal_double), dl or DL (decimal_long_double), and dll or DLL (decimal_long_long_double). However, the suffix does not determine the final numerical precision: that is set by the declared precision of the conversion function.
Lettercase is not significant in Infinity and NaN representations. Acceptable strings include ones like these:
Inf -INFINITY +INF -NaN(0xfeedface) NaN(0xfacade) -NaN +NaN QNAN(0x1234) +QNAN(0xacceded) +QNAN QNAN SNaN(0xbead6789) snan(0xbeef) -snan(0XEFFACEABLE) SNAN(cafe_feed) -snan snan SNaN SNAN
Although all IEEE 754 floating-point designs support a sign on NaNs, the sign has no significance.
In the current implementation, a parenthesized hexadecimal tag, optionally prefixed with 0x or 0X, and possibly containing underscore digit separators, is recognized in a NaN as long as the parentheses are balanced, and low-order bits of the tag are installed in the payload bits of the significand of the NaN.
QNaN (quiet NaN) and SNaN (signaling NaN) are distinguishable on most systems, except on the widely-used Intel IA-32 architecture, the Java Virtual Machine, and possibly also the Microsoft .NET Framework Common Language Infrastructure (CLI) virtual machine.
The global variable errno defined in <errno.h> is set to EDOM for NaN conversion, and to ERANGE if a numeric string underflows or overflows. Conversion of Infinity strings does not set errno.