https://issues.dlang.org/show_bug.cgi?id=14958
--- Comment #4 from Steven Schveighoffer <[email protected]> --- (In reply to yebblies from comment #3) > This is working to spec. Please re-open as an enhancement request if you > feel it's necessary. I think the expectation is violated when there is a measurable difference between treating a value as a real and treating it as a double, and the compiler is doing things under the hood that cannot be detected that force the calculation to be done with reals. For instance: double x = 1.2; auto y = x * 10.0; pragma(msg, typeof(y)); // double pragma(msg, typeof(x * 10.0)); // double writefln("%s %s", cast(ulong)y, cast(ulong)(x * 10.0)); // 12 11 Clearly, treating the result as a double should result in 12. But it doesn't. And there's no rhyme or reason why 'y' above should be any different from the result of the expression (x * 10.0). This violates the principal of refactoring calculations by assigning them to variables. I don't want the result of my code to change if I have to create a temporary using auto. Two ways to fix are: 1) treat the result of an expression typed as a double as a double (perform the rounding) or 2) typeof(double op double) should be real. I'm not going to reopen, because I don't have any personal interest in fighting for this. But I can definitely see where D has gone wrong here. --
