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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/impl-trait/example-st.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 'src/test/ui/impl-trait/example-st.rs')
-rw-r--r-- | src/test/ui/impl-trait/example-st.rs | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/test/ui/impl-trait/example-st.rs b/src/test/ui/impl-trait/example-st.rs new file mode 100644 index 000000000..4e1aa3a08 --- /dev/null +++ b/src/test/ui/impl-trait/example-st.rs @@ -0,0 +1,30 @@ +// run-pass + +struct State; +type Error = (); + +trait Bind<F> { + type Output; + fn bind(self, f: F) -> Self::Output; +} + +fn bind<T, U, A, B, F>(mut a: A, mut f: F) + -> impl FnMut(&mut State) -> Result<U, Error> +where F: FnMut(T) -> B, + A: FnMut(&mut State) -> Result<T, Error>, + B: FnMut(&mut State) -> Result<U, Error> +{ + move |state | { + let r = a(state)?; + f(r)(state) + } +} + +fn atom<T>(x: T) -> impl FnMut(&mut State) -> Result<T, Error> { + let mut x = Some(x); + move |_| x.take().map_or(Err(()), Ok) +} + +fn main() { + assert_eq!(bind(atom(5), |x| atom(x > 4))(&mut State), Ok(true)); +} |