pub struct RangeTo<Idx> {
    pub end: Idx,
}🔬This is a nightly-only experimental API. (
new_range_api)Expand description
A range only bounded exclusively above (..end).
The RangeTo ..end contains all values with x < end.
It cannot serve as an Iterator because it doesn’t have a starting point.
§Examples
The ..end syntax is a RangeTo:
assert_eq!((..5), std::ops::RangeTo { end: 5 });It does not have an IntoIterator implementation, so you can’t use it in
a for loop directly. This won’t compile: