From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- tests/ui/never_type/try_from.rs | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 tests/ui/never_type/try_from.rs (limited to 'tests/ui/never_type/try_from.rs') diff --git a/tests/ui/never_type/try_from.rs b/tests/ui/never_type/try_from.rs new file mode 100644 index 000000000..50451576f --- /dev/null +++ b/tests/ui/never_type/try_from.rs @@ -0,0 +1,37 @@ +// run-pass +// This test relies on `TryFrom` being blanket impl for all `T: Into` +// and `TryInto` being blanket impl for all `U: TryFrom` + +// This test was added to show the motivation for doing this +// over `TryFrom` being blanket impl for all `T: From` + +#![feature(never_type)] + +use std::convert::{TryInto, Infallible}; + +struct Foo { + t: T, +} + +// This fails to compile due to coherence restrictions +// as of Rust version 1.32.x, therefore it could not be used +// instead of the `Into` version of the impl, and serves as +// motivation for a blanket impl for all `T: Into`, instead +// of a blanket impl for all `T: From` +/* +impl From> for Box { + fn from(foo: Foo) -> Box { + Box::new(foo.t) + } +} +*/ + +impl Into> for Foo { + fn into(self) -> Vec { + vec![self.t] + } +} + +pub fn main() { + let _: Result, Infallible> = Foo { t: 10 }.try_into(); +} -- cgit v1.2.3