Maybe I'm just totally missing something, but this seems really wrong to me.
This program:
import std.stdio;
void main()
{
writeln(2.1);
writeln(2.1 == 2.1);
writeln(3 * .7);
writeln(2.1 == 3 * .7);
auto a = 2.1;
auto b = 3 * .7;
writeln(a);
writeln(b);
writeln(a == b);
}
prints out
2.1
true
2.1
false
2.1
2.1
true
How on earth is 2.1 not equal to 3 * .7? Adding extra parens doesn't help, so
it's not an operator precedence issue or anything like that. For some reason,
the result of 3 * .7 is not considered to be equal to the literal 2.1. What's
the deal? As I understand it, floating point operations at compile time do not
necessarily match those done at runtime, but 2.1 should be plenty exact for
both
compile time and runtime. It's not like there are a lot of digits in the
number,
and it prints out 2.1 whether you're dealing with a variable or a literal.
What's the deal here? Is this a bug? Or am I just totally misunderstanding
something?
- Jonathan M Davis
