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// run-pass pub trait MyNum { fn from_int(_: isize) -> Self; } pub trait NumExt: MyNum { } struct S { v: isize } impl MyNum for S { fn from_int(i: isize) -> S { S { v: i } } } impl NumExt for S { } fn greater_than_one<T:NumExt>() -> T { MyNum::from_int(1) } pub fn main() { let v: S = greater_than_one(); assert_eq!(v.v, 1); }