On 19.02.2019 18:07, Dennis wrote:
On Tuesday, 19 February 2019 at 14:34:09 UTC, drug wrote:
Now I do it this way (https://run.dlang.io/is/8kVibT):
```
    auto some_duration = dur!"msecs"(500);
    auto seconds = some_duration.total!"hnsecs" / 10_000_000.0;
    assert(seconds.approxEqual(0.5));
```
is there better way to do it?


What you're doing now is the way to do it. This is by design, as Jonathan M. Davis explains:

"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.
(...)
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."

https://forum.dlang.org/post/[email protected]



Well, I understand that using floating point values to represent time internally is a bad idea and I totally agree. But some convenient API to convert Duration to floating point and vice versa would be useful because in mechanics for example you often need to express time in seconds with fractional part. In this regard std::chrono is more expressive (the only one though, in general std.datetime is much more powerful than std::chrono).

Reply via email to