Skip to content

Remember to check the name of the associated type being projected when s... #20655

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 7, 2015
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 9 additions & 1 deletion src/librustc/middle/traits/project.rs
Original file line number Diff line number Diff line change
Expand Up @@ -452,7 +452,9 @@ fn assemble_candidates_from_predicates<'cx,'tcx>(
for predicate in elaborate_predicates(selcx.tcx(), env_predicates) {
match predicate {
ty::Predicate::Projection(ref data) => {
let is_match = infcx.probe(|_| {
let same_name = data.item_name() == obligation.predicate.item_name;

let is_match = same_name && infcx.probe(|_| {
let origin = infer::Misc(obligation.cause.span);
let obligation_poly_trait_ref =
obligation_trait_ref.to_poly_trait_ref();
Expand All @@ -465,6 +467,9 @@ fn assemble_candidates_from_predicates<'cx,'tcx>(
});

if is_match {
debug!("assemble_candidates_from_predicates: candidate {}",
data.repr(selcx.tcx()));

candidate_set.vec.push(
ProjectionTyCandidate::ParamEnv(data.clone()));
}
Expand Down Expand Up @@ -527,6 +532,9 @@ fn assemble_candidates_from_impls<'cx,'tcx>(

match vtable {
super::VtableImpl(data) => {
debug!("assemble_candidates_from_impls: impl candidate {}",
data.repr(selcx.tcx()));

candidate_set.vec.push(
ProjectionTyCandidate::Impl(data));
}
Expand Down
4 changes: 4 additions & 0 deletions src/librustc/middle/ty.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1866,6 +1866,10 @@ pub struct ProjectionPredicate<'tcx> {
pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;

impl<'tcx> PolyProjectionPredicate<'tcx> {
pub fn item_name(&self) -> ast::Name {
self.0.projection_ty.item_name // safe to skip the binder to access a name
}

pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
self.0.projection_ty.sort_key()
}
Expand Down
56 changes: 56 additions & 0 deletions src/test/compile-fail/associated-types-multiple-types-one-trait.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,56 @@
// 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

trait Foo {
type X;
type Y;
}

fn have_x_want_x<T:Foo<X=u32>>(t: &T)
{
want_x(t);
}

fn have_x_want_y<T:Foo<X=u32>>(t: &T)
{
want_y(t); //~ ERROR type mismatch
}

fn have_y_want_x<T:Foo<Y=i32>>(t: &T)
{
want_x(t); //~ ERROR type mismatch
}

fn have_y_want_y<T:Foo<Y=i32>>(t: &T)
{
want_y(t);
}

fn have_xy_want_x<T:Foo<X=u32,Y=i32>>(t: &T)
{
want_x(t);
}

fn have_xy_want_y<T:Foo<X=u32,Y=i32>>(t: &T)
{
want_y(t);
}

fn have_xy_want_xy<T:Foo<X=u32,Y=i32>>(t: &T)
{
want_x(t);
want_y(t);
}

fn want_x<T:Foo<X=u32>>(t: &T) { }

fn want_y<T:Foo<Y=i32>>(t: &T) { }

fn main() { }