[avr-libc-dev] [bug #38614] dtostrf - wrong behavior or wrong documentation

[Anton]

URL:
  <http://savannah.nongnu.org/bugs/?38614>

                 Summary: dtostrf - wrong behavior or wrong documentation
                 Project: AVR C Runtime Library
            Submitted by: demiurg_spb
            Submitted on: Чтв 28 Мар 2013 07:54:26
                Category: Library
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: libc code
                  Status: None
        Percent Complete: 0%
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 1.8.0
           Fixed Release: None

    _______________________________________________________

Details:

I have next situation: 
Code:
float value = 0.0f; 
char buf[32]; 
static const int WIDTH = 3; 
static const int PREC  = 0; 
dtostrf(value, WIDTH, PREC, buf);

I get {' ',' ','0'} // space, space, zero 
but I expected {' ','0','.'} // space, zero, point 
because of manual: 
Quote:
The minimum field width of the output string (including the '.' and the
possible sign for negative values) is given in width, and prec determines the
number of digits after the decimal sign. width is signed value, negative for
left adjustment.

I think manual sholud be corrected: 
Quote:
The minimum field width of the output string (including the possible '.' and
the possible sign for negative values) is given in width, and prec determines
the number of digits after the decimal sign. width is signed value, negative
for left adjustment.

Jörg Wunsch comment from avrfreaks:

That's debatable. It would seem reasonable to correct the function 
itself, so it yields " 0." rather than " 0", to indicate this is 
a floating-point number. Then, it would also be debatable how to 
handle numbers where the absolute value is less than one: print 
" .1", or better " 0.1"? 





    _______________________________________________________

Reply to this item at:

  <http://savannah.nongnu.org/bugs/?38614>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.nongnu.org/