[cloogshicer]

I think this is the best answer.

This got me thinking: What about a situation where the accuracy is given in a real-life unit. For example, the accuracy of a GPS measurement, given in meters. I've sometimes used names like 'accuracyInMeters' to represent this, but it felt a bit cumbersome.

Edit: Thinking more about it, I guess you could typealias Float to Meters, or something like that, but also feels weird to me.

[andrewaylett]

More complex type systems absolutely support asserting the units of a value in the type system. For example, here's an implementation of SI types in C++: https://github.com/bernedom/SI

[sriku]

I've used "fraction" for this purpose .. but that isn't general enough. In fact a convention I've used for nearly 2 decades has been varName_unit .. where the part after the underscore (with the preceding part being camel case) indicates the unit of the value. So (x_frac, y_frac) are normalized screen coordinates whereas (x_px, y_px) would be pixel unit coordinates. Others are like freq_hz, duration_secs and so on.

[GuB-42]

I usually do the "inMeters" thing.

Another thing you can do is define a "METER" constant equal to 1. You can then call your function like this: func(1.5 * METER), and when you need a number of meters, you can do "accuracy / METER". The multiplication and division should be optimized away.

Good thing about that is that you can specify the units you want, for example you can set FOOT to 0.3048 and do "5. * FOOT" and get back your result in centimeters by doing "accuracy / CENTIMETER". The last conversion is not free if the internal representation is in meter but at least, you can do it and it is readable.

If you are going to use such distances a lot, at least in C++, you can get a bit of help from the type system. Define a "distance" class operator overloads, constants and convenience functions to enforce consistent units. Again, the optimizer should make it not more costly than using raw floats if that's what you decide to use as an internal representation.

[Serow225]

F# has 'units of measure' support, https://docs.microsoft.com/en-us/dotnet/fsharp/language-refe...

[eru]

Some languages provide more than just an alias. Eg Haskell lets you wrap your Float in a 'newtype' like 'GpsInMeters'.

The newtype wrapper doesn't show up at runtime, only at compile time. It can be set up in such a way that the compiler complains about adding GpsInMeters to GpsInMiles naively.

[clusterfish]

That's what unboxed tagged types are for. Floats (e.g.) at runtime, but with compile time restrictions.