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-rw-r--r--src/test/ui/drop/dropck-eyepatch.rs102
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diff --git a/src/test/ui/drop/dropck-eyepatch.rs b/src/test/ui/drop/dropck-eyepatch.rs
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--- a/src/test/ui/drop/dropck-eyepatch.rs
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@@ -1,102 +0,0 @@
-// run-pass
-#![feature(dropck_eyepatch)]
-
-// The point of this test is to illustrate that the `#[may_dangle]`
-// attribute specifically allows, in the context of a type
-// implementing `Drop`, a generic parameter to be instantiated with a
-// lifetime that does not strictly outlive the owning type itself.
-//
-// Here we test that a model use of `#[may_dangle]` will compile and run.
-//
-// The illustration is made concrete by comparison with two variations
-// on the type with `#[may_dangle]`:
-//
-// 1. an analogous type that does not implement `Drop` (and thus
-// should exhibit maximal flexibility with respect to dropck), and
-//
-// 2. an analogous type that does not use `#[may_dangle]` (and thus
-// should exhibit the standard limitations imposed by dropck.
-//
-// The types in this file follow a pattern, {D,P,S}{t,r}, where:
-//
-// - D means "I implement Drop"
-//
-// - P means "I implement Drop but guarantee my (first) parameter is
-// pure, i.e., not accessed from the destructor"; no other parameters
-// are pure.
-//
-// - S means "I do not implement Drop"
-//
-// - t suffix is used when the first generic is a type
-//
-// - r suffix is used when the first generic is a lifetime.
-
-trait Foo { fn foo(&self, _: &str); }
-
-struct Dt<A: Foo>(&'static str, A);
-struct Dr<'a, B:'a+Foo>(&'static str, &'a B);
-struct Pt<A,B: Foo>(&'static str, #[allow(unused_tuple_struct_fields)] A, B);
-struct Pr<'a, 'b, B:'a+'b+Foo>(&'static str, #[allow(unused_tuple_struct_fields)] &'a B, &'b B);
-struct St<A: Foo>(&'static str, #[allow(unused_tuple_struct_fields)] A);
-struct Sr<'a, B:'a+Foo>(&'static str, #[allow(unused_tuple_struct_fields)] &'a B);
-
-impl<A: Foo> Drop for Dt<A> {
- fn drop(&mut self) { println!("drop {}", self.0); self.1.foo(self.0); }
-}
-impl<'a, B: Foo> Drop for Dr<'a, B> {
- fn drop(&mut self) { println!("drop {}", self.0); self.1.foo(self.0); }
-}
-unsafe impl<#[may_dangle] A, B: Foo> Drop for Pt<A, B> {
- // (unsafe to access self.1 due to #[may_dangle] on A)
- fn drop(&mut self) { println!("drop {}", self.0); self.2.foo(self.0); }
-}
-unsafe impl<#[may_dangle] 'a, 'b, B: Foo> Drop for Pr<'a, 'b, B> {
- // (unsafe to access self.1 due to #[may_dangle] on 'a)
- fn drop(&mut self) { println!("drop {}", self.0); self.2.foo(self.0); }
-}
-
-fn main() {
- use std::cell::RefCell;
-
- impl Foo for RefCell<String> {
- fn foo(&self, s: &str) {
- let s2 = format!("{}|{}", *self.borrow(), s);
- *self.borrow_mut() = s2;
- }
- }
-
- impl<'a, T:Foo> Foo for &'a T {
- fn foo(&self, s: &str) {
- (*self).foo(s);
- }
- }
-
- struct CheckOnDrop(RefCell<String>, &'static str);
- impl Drop for CheckOnDrop {
- fn drop(&mut self) { assert_eq!(*self.0.borrow(), self.1); }
- }
-
- let c_long;
- let (c, dt, dr, pt, pr, st, sr)
- : (CheckOnDrop, Dt<_>, Dr<_>, Pt<_, _>, Pr<_>, St<_>, Sr<_>);
- c_long = CheckOnDrop(RefCell::new("c_long".to_string()),
- "c_long|pr|pt|dr|dt");
- c = CheckOnDrop(RefCell::new("c".to_string()),
- "c");
-
- // No error: sufficiently long-lived state can be referenced in dtors
- dt = Dt("dt", &c_long.0);
- dr = Dr("dr", &c_long.0);
-
- // No error: Drop impl asserts .1 (A and &'a _) are not accessed
- pt = Pt("pt", &c.0, &c_long.0);
- pr = Pr("pr", &c.0, &c_long.0);
-
- // No error: St and Sr have no destructor.
- st = St("st", &c.0);
- sr = Sr("sr", &c.0);
-
- println!("{:?}", (dt.0, dr.0, pt.0, pr.0, st.0, sr.0));
- assert_eq!(*c_long.0.borrow(), "c_long");
- assert_eq!(*c.0.borrow(), "c");
-}