mirror of https://github.com/rust-lang/rust
38 lines
919 B
Rust
38 lines
919 B
Rust
//@ run-pass
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// This test relies on `TryFrom` being blanket impl for all `T: Into`
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// and `TryInto` being blanket impl for all `U: TryFrom`
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// This test was added to show the motivation for doing this
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// over `TryFrom` being blanket impl for all `T: From`
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#![feature(never_type)]
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use std::convert::{TryInto, Infallible};
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struct Foo<T> {
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t: T,
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}
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// This fails to compile due to coherence restrictions
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// as of Rust version 1.32.x, therefore it could not be used
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// instead of the `Into` version of the impl, and serves as
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// motivation for a blanket impl for all `T: Into`, instead
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// of a blanket impl for all `T: From`
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/*
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impl<T> From<Foo<T>> for Box<T> {
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fn from(foo: Foo<T>) -> Box<T> {
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Box::new(foo.t)
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}
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}
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*/
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impl<T> Into<Vec<T>> for Foo<T> {
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fn into(self) -> Vec<T> {
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vec![self.t]
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}
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}
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pub fn main() {
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let _: Result<Vec<i32>, Infallible> = Foo { t: 10 }.try_into();
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}
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