On Monday, 5 June 2017 at 15:37:42 UTC, Steven Schveighoffer
wrote:
It appears that the precision parameter in std.format differs
from its meaning in printf. Is that expected behavior?
Example:
import std.stdio;
import core.stdc.stdio;
void main()
{
auto f = 20.66666;
writeln(f);
writefln("%0.3s", f);
printf("%0.3f\n", f);
}
prints:
20.6667
20.7
20.667
It appears that the precision specifier is dictating the total
number of digits on *both sides* of the decimal place. Whereas,
in C, it's only the number of digits *after* the decimal place.
I'm trying to specify 3 places of precision after the decimal.
How do I do this easily?
I'm having a hard time believing this behavior has never been
reported, but I can't find anything about it in bugzilla.
Tested all the way back to 2.040.
-Steve
You do realize that you have used "s" in the D version?
This works as expected:
writefln("%0.3f", f); // 20.667
printf("%0.3f\n", f); // 20.667
This is a bit more interesting:
writefln("%0.3s", f); // 20.7
printf("%0.3s\n", f); // 20.
