the "general" floating point format
Mon Jan 2 06:39:00 GMT 2006
On Mon, 2 Jan 2006 02:48 pm, Ian Lance Taylor wrote:
> Anthony Shipman <firstname.lastname@example.org> writes:
> > Is there a precise specification of how printf() decides whether to use
> > the fixed point or scientific format when the format is "general"?
> I assume you are referring to %g. The answer is yes. From the
> GNU/Linux man page, for example (man 3 printf):
> The double argument is converted in style f or e (or F or E for G
> conversions). The precision specifies the number of significant
> digits. If the precision is missing, 6 digits are given; if the
> precision is zero, it is treated as 1. Style e is used if the
> exponent from its conversion is less than -4 or greater than or
> equal to the precision. Trailing zeros are removed from the
> fractional part of the result; a decimal point appears only if it
> is followed by at least one digit.
Oh, I missed that bit in the middle. Is that the C standard or just how Gnu C
Do you know if libstdc++ uses exactly the same specification or perhaps
delegates to printf()? (I started off searching for how the C++ "general"
format was defined).
Anthony Shipman Mamas don't let your babies
email@example.com grow up to be outsourced.
More information about the Gcc-help