On Monday, 24 August 2015 at 16:52:54 UTC, Márcio Martins wrote:
I'm posting this here for visibility. This was silently
corrupting our data, and might be doing the same for others as
well.
import std.stdio;
void main() {
double x = 1.2;
writeln(cast(ulong)(x * 10.0));
double y = 1.2 * 10.0;
writeln(cast(ulong)y);
}
Output:
11
12
to!ulong instead of the cast does the right thing, and is a
viable work-around.
Issue: https://issues.dlang.org/show_bug.cgi?id=14958)
I would not describe to!ulong as a "work-around". You just
discovered one of the reasons to! exists: it is the right way to
do it and cast(ulong) is the wrong way. As the others have noted,
floating point is tricky business, and you need to use the right
tools for the job.
std.math.round also works.
