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Update 'Subtyping and Variance' example to use dyn Trait syntax #1110

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Nov 27, 2021
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Update 'Subtyping and Variance' example to use dyn Trait syntax #1110

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4 changes: 2 additions & 2 deletions src/subtyping.md
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Original file line number Diff line number Diff line change
Expand Up @@ -29,8 +29,8 @@ let subtype: &(for<'a> fn(&'a i32) -> &'a i32) = &((|x| x) as fn(&_) -> &_);
let supertype: &(fn(&'static i32) -> &'static i32) = subtype;

// This works similarly for trait objects
let subtype: &(for<'a> Fn(&'a i32) -> &'a i32) = &|x| x;
let supertype: &(Fn(&'static i32) -> &'static i32) = subtype;
let subtype: &(dyn for<'a> Fn(&'a i32) -> &'a i32) = &|x| x;
let supertype: &(dyn Fn(&'static i32) -> &'static i32) = subtype;

// We can also substitute one higher-ranked lifetime for another
let subtype: &(for<'a, 'b> fn(&'a i32, &'b i32))= &((|x, y| {}) as fn(&_, &_));
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