e81ae40770
That is, when offering suggestions for unresolved method calls, avoid
suggesting traits for which implementing the trait for the receiver type
either makes little sense (e.g. type errors, or sugared unboxed
closures), or violates coherence.
The latter is approximated by ensuring that at least one of `{receiver
type, trait}` is local. This isn't precisely correct due to
multidispatch, but the error messages one encounters in such situation
are useless more often than not; it is better to be conservative and
miss some cases, than have overly many false positives (e.g. writing
`some_slice.map(|x| ...)` uselessly suggested that one should implement
`IteratorExt` for `&[T]`, while the correct fix is to call `.iter()`).
Closes #21420.
135 lines
5.7 KiB
Rust
135 lines
5.7 KiB
Rust
// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// aux-build:no_method_suggested_traits.rs
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extern crate no_method_suggested_traits;
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struct Foo;
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enum Bar { X }
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mod foo {
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trait Bar {
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fn method(&self) {}
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fn method2(&self) {}
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}
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impl Bar for u32 {}
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impl Bar for char {}
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}
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fn main() {
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// test the values themselves, and autoderef.
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1u32.method();
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//~^ HELP following traits are implemented but not in scope, perhaps add a `use` for one of them
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//~^^ ERROR does not implement
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//~^^^ HELP `foo::Bar`
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//~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
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std::rc::Rc::new(&mut Box::new(&1u32)).method();
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//~^ HELP following traits are implemented but not in scope, perhaps add a `use` for one of them
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//~^^ ERROR does not implement
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//~^^^ HELP `foo::Bar`
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//~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
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'a'.method();
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//~^ ERROR does not implement
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//~^^ HELP the following trait is implemented but not in scope, perhaps add a `use` for it:
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//~^^^ HELP `foo::Bar`
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std::rc::Rc::new(&mut Box::new(&'a')).method();
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//~^ ERROR does not implement
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//~^^ HELP the following trait is implemented but not in scope, perhaps add a `use` for it:
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//~^^^ HELP `foo::Bar`
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1i32.method();
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//~^ ERROR does not implement
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//~^^ HELP the following trait is implemented but not in scope, perhaps add a `use` for it:
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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std::rc::Rc::new(&mut Box::new(&1i32)).method();
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//~^ ERROR does not implement
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//~^^ HELP the following trait is implemented but not in scope, perhaps add a `use` for it:
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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Foo.method();
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//~^ ERROR does not implement
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//~^^ HELP following traits define a method `method`, perhaps you need to implement one of them
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//~^^^ HELP `foo::Bar`
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//~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
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//~^^^^^ HELP `no_method_suggested_traits::reexport::Reexported`
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//~^^^^^^ HELP `no_method_suggested_traits::bar::PubPriv`
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//~^^^^^^^ HELP `no_method_suggested_traits::qux::PrivPub`
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//~^^^^^^^^ HELP `no_method_suggested_traits::quz::PrivPriv`
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std::rc::Rc::new(&mut Box::new(&Foo)).method();
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//~^ ERROR does not implement
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//~^^ HELP following traits define a method `method`, perhaps you need to implement one of them
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//~^^^ HELP `foo::Bar`
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//~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
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//~^^^^^ HELP `no_method_suggested_traits::reexport::Reexported`
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//~^^^^^^ HELP `no_method_suggested_traits::bar::PubPriv`
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//~^^^^^^^ HELP `no_method_suggested_traits::qux::PrivPub`
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//~^^^^^^^^ HELP `no_method_suggested_traits::quz::PrivPriv`
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1u64.method2();
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//~^ ERROR does not implement
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//~^^ HELP the following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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std::rc::Rc::new(&mut Box::new(&1u64)).method2();
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//~^ ERROR does not implement
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//~^^ HELP the following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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no_method_suggested_traits::Foo.method2();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Foo)).method2();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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no_method_suggested_traits::Bar::X.method2();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Bar::X)).method2();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method2`, perhaps you need to implement it
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//~^^^ HELP `foo::Bar`
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Foo.method3();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method3`, perhaps you need to implement it
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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std::rc::Rc::new(&mut Box::new(&Foo)).method3();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method3`, perhaps you need to implement it
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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Bar::X.method3();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method3`, perhaps you need to implement it
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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std::rc::Rc::new(&mut Box::new(&Bar::X)).method3();
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//~^ ERROR does not implement
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//~^^ HELP following trait defines a method `method3`, perhaps you need to implement it
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//~^^^ HELP `no_method_suggested_traits::foo::PubPub`
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// should have no help:
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1us.method3(); //~ ERROR does not implement
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std::rc::Rc::new(&mut Box::new(&1us)).method3(); //~ ERROR does not implement
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no_method_suggested_traits::Foo.method3(); //~ ERROR does not implement
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std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Foo)).method3();
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//~^ ERROR does not implement
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no_method_suggested_traits::Bar::X.method3(); //~ ERROR does not implement
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std::rc::Rc::new(&mut Box::new(&no_method_suggested_traits::Bar::X)).method3();
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//~^ ERROR does not implement
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}
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