On Tuesday, 25 August 2015 at 11:14:35 UTC, Steven Schveighoffer
wrote:
On 8/24/15 5:34 PM, "=?UTF-8?B?Ik3DoXJjaW8=?= Martins\"
<marcio...@gmail.com>\"" wrote:
On Monday, 24 August 2015 at 21:03:50 UTC, Steven
Schveighoffer wrote:
I understand the inconsistency, and I agree it is an issue
that should
be examined. But the issue is entirely avoidable by not using
incorrect methods to convert from floating point to integer
after
floating point operations introduce some small level of error.
Perhaps there is some way to make it properly round in this
case, but
I guarantee it will not fix all floating point errors.
What is the correct way to truncate, not round, a
floating-point value
to an integer?
auto result = cast(ulong)(x * 10.0 + x.epsilon);
-Steve
import std.stdio;
void main() {
double x = 1.2;
writeln(cast(ulong)(x * 10.0 + x.epsilon));
double y = x * 10.0;
writeln(cast(ulong)(y + x.epsilon));
double z = x * 10.0 + x.epsilon;
writeln(cast(ulong)(z));
}
Outputs:
11
12
12
I leave it at this. It seems like this only bothers me, and I
have no more time to argue.
The workaround is not that bad, and at the end of the day, it is
just one more thing on the list.
