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-rw-r--r--src/test/ui/higher-rank-trait-bounds/hrtb-just-for-static.rs35
1 files changed, 35 insertions, 0 deletions
diff --git a/src/test/ui/higher-rank-trait-bounds/hrtb-just-for-static.rs b/src/test/ui/higher-rank-trait-bounds/hrtb-just-for-static.rs
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index 000000000..8fb4218f8
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+++ b/src/test/ui/higher-rank-trait-bounds/hrtb-just-for-static.rs
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+// Test a case where you have an impl of `Foo<X>` for all `X` that
+// is being applied to `for<'a> Foo<&'a mut X>`. Issue #19730.
+
+trait Foo<X> {
+ fn foo(&self, x: X) { }
+}
+
+fn want_hrtb<T>()
+ where T : for<'a> Foo<&'a isize>
+{
+}
+
+// AnyInt implements Foo<&'a isize> for any 'a, so it is a match.
+struct AnyInt;
+impl<'a> Foo<&'a isize> for AnyInt { }
+fn give_any() {
+ want_hrtb::<AnyInt>()
+}
+
+// StaticInt only implements Foo<&'static isize>, so it is an error.
+struct StaticInt;
+impl Foo<&'static isize> for StaticInt { }
+fn give_static() {
+ want_hrtb::<StaticInt>() //~ ERROR
+}
+
+// &'a u32 only implements Foo<&'a isize> for specific 'a, so it is an error.
+impl<'a> Foo<&'a isize> for &'a u32 { }
+fn give_some<'a>() {
+ want_hrtb::<&'a u32>()
+ //~^ ERROR lifetime may not live long enough
+ //~| ERROR implementation of `Foo` is not general enough
+}
+
+fn main() { }