From ff388c12770dd8aa33ed48595f780d2aa49cd5d2 Mon Sep 17 00:00:00 2001 From: Niko Matsakis Date: Tue, 17 Feb 2015 10:57:15 -0500 Subject: Traits that reference `Self` in the supertrait list are not object-safe. Fixes #22040. --- src/test/compile-fail/object-safety-issue-22040.rs | 50 ++++++++++++++++++++++ .../object-safety-supertrait-mentions-Self.rs | 32 ++++++++++++++ 2 files changed, 82 insertions(+) create mode 100644 src/test/compile-fail/object-safety-issue-22040.rs create mode 100644 src/test/compile-fail/object-safety-supertrait-mentions-Self.rs (limited to 'src/test') diff --git a/src/test/compile-fail/object-safety-issue-22040.rs b/src/test/compile-fail/object-safety-issue-22040.rs new file mode 100644 index 00000000000..edf32131b68 --- /dev/null +++ b/src/test/compile-fail/object-safety-issue-22040.rs @@ -0,0 +1,50 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Regression test for #22040. + +use std::fmt::Debug; + +trait Expr: Debug + PartialEq { + fn print_element_count(&self); +} + +//#[derive(PartialEq)] +#[derive(Debug)] +struct SExpr<'x> { + elements: Vec>, +} + +impl<'x> PartialEq for SExpr<'x> { + fn eq(&self, other:&SExpr<'x>) -> bool { + println!("L1: {} L2: {}", self.elements.len(), other.elements.len()); + let result = self.elements.len() == other.elements.len(); + + println!("Got compare {}", result); + return result; + } +} + +impl <'x> SExpr<'x> { + fn new() -> SExpr<'x> { return SExpr{elements: Vec::new(),}; } +} + +impl <'x> Expr for SExpr<'x> { + fn print_element_count(&self) { + println!("element count: {}", self.elements.len()); + } +} + +fn main() { + let a: Box = Box::new(SExpr::new()); //~ ERROR trait `Expr` is not object-safe + let b: Box = Box::new(SExpr::new()); //~ ERROR trait `Expr` is not object-safe + + assert_eq!(a , b); +} diff --git a/src/test/compile-fail/object-safety-supertrait-mentions-Self.rs b/src/test/compile-fail/object-safety-supertrait-mentions-Self.rs new file mode 100644 index 00000000000..d3f9dc73020 --- /dev/null +++ b/src/test/compile-fail/object-safety-supertrait-mentions-Self.rs @@ -0,0 +1,32 @@ +// Copyright 2014 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Check that we correctly prevent users from making trait objects +// form traits that make use of `Self` in an argument or return position. + +trait Bar { + fn bar(&self, x: &T); +} + +trait Baz : Bar { +} + +fn make_bar>(t: &T) -> &Bar { + t +} + +fn make_baz(t: &T) -> &Baz { + t + //~^ ERROR `Baz` is not object-safe + //~| NOTE the trait cannot use `Self` as a type parameter in the supertrait listing +} + +fn main() { +} -- cgit 1.4.1-3-g733a5