On Monday, 18 January 2016 at 12:46:31 UTC, Jonathan M Davis
wrote:
In general, using floating point values with time is an
incredibly bad idea. It can certainly make sense when printing
stuff out, but using it in calculations is just asking for
trouble given all of the unnecessary imprecision that it adds.
So, Duration does not directly support floating point values at
all, and that's very much on purpose. I'd strongly argue that
the fact that TickDuration does was a mistake.
So, if you're doing floating point calculations with time, I'd
strongly urge you to rethink your code. And if you're just
trying to print out the a duration as a floating point value,
because it's nice to view that way, then that's fine, but
you'll need to do the conversion yourself. And it's not that
hard. It just isn't handed to you directly, because aside from
printing, code really shouldn't be using floating point values
for time. e.g.
string toFloatingSeconds(Duration d)
{
import std.conv;
enum hnsecsPerSecond = convert!("seconds", "hnsecs")(1);
auto s = d.split!("seconds", "hnsecs")();
return to!string(s.seconds + cast(real)(s.hnsecs) /
hnsecsPerSecond);
}
And yes, that's a bit more of a pain than using to!("seconds",
float) with TickDuration, but it's also the sort of thing that
most code really shouldn't be doing. So, adding that
functionality to Duration would just encourage folks to write
buggy code.
- Jonathan M Davis
I want to use float time in a game where I call the update method
passing the delta time as float seconds. It's more easy to
multiply the dt with a speed constant meaning how much the object
will move after 1 second. Such float delta time is used in many
game engines and it's somewhat standart way of doing it. Also the
method you wrote returns a string and I need a float to multiply
it with a number.
Thanks for the reply anyway
