Impl Copy for Range #2848
Description
From rust-lang/rust#48649 (closed as needing an RFC): It would be nice for Range<Idx: Copy> to implement Copy.
I want to store a Range in a struct, but that prevents me from making the struct Copy. I can make a (start, end) struct that wraps it but that seems a little silly.
With Range from the standard library (playground):
use core::ops::Range;
// error[E0204]: the trait `Copy` may not be implemented for this type
#[derive(Copy)]
struct HasRange {
r: Range<usize>,
other_field: usize,
}
// works fine
struct HasRangeWrapper {
r: RangeWrapper,
other_field: usize,
}
#[derive(Copy, Clone)]
pub struct RangeWrapper {
start: usize,
end: usize,
}
// Note that Range is isomorphic to RangeWrapper;
// you can convert freely between the two
impl From<Range<usize>> for RangeWrapper {
fn from(range: Range<usize>) -> Self {
Self { start: range.start, end: range.end }
}
}
impl From<RangeWrapper> for Range<usize> {
fn from(range: RangeWrapper) -> Self {
Self { start: range.start, end: range.end }
}
}There is more discussion of pros and cons in the rust-lang/rust issue.