I have some traits and their methods implemented for &[T] but when I call them on &[f64], I get type conflict. T:Into+From<f64> as trait bound does not help either. Which seems to defeat the objective of having generics in the first place. I need all numeric types, and f64 specifically, to be accepted as T. Is there any way around this?
Do I need to implement somehow T:From<f64> explicitly and if so, how and why?
It's not clear to me at all what exactly the problem is that you're facing. Maybe some code example(s) would help illustrate.
For example, I get error: expected &[T] found &[f64] in median call
fn mad(self,median:f64) -> Result<f64> {
let diffs:Vec<f64> = self.iter().map(|&s| ((f64::from(s)-median).abs())).collect();
Ok(medians::median(diffs.as_slice()))
}
where the signature of median is:
pub fn median<T>(set:&[T]) -> f64
where T: Copy+PartialOrd,f64:From<T>
I used to get around this by defining additional:
pub fn medianf64(set:&[f64]) -> f64
But, as I say, it totally defeats the object of having generics in the first place. There must be some way?
Does this change fix it?
- Ok(medians::median(diffs.as_slice()))
+ Ok(medians::median::<f64>(diffs.as_slice()))
Wow, the turbo-fish! Did not think of that. What a secret! Thank you so much!!!
Must not let these things get us down, eh? 