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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/never_type/try_from.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/test/ui/never_type/try_from.rs | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/ui/never_type/try_from.rs b/src/test/ui/never_type/try_from.rs new file mode 100644 index 000000000..50451576f --- /dev/null +++ b/src/test/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: 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<T> From<Foo<T>> for Box<T> { + fn from(foo: Foo<T>) -> Box<T> { + Box::new(foo.t) + } +} +*/ + +impl<T> Into<Vec<T>> for Foo<T> { + fn into(self) -> Vec<T> { + vec![self.t] + } +} + +pub fn main() { + let _: Result<Vec<i32>, Infallible> = Foo { t: 10 }.try_into(); +} |