rust/crates/hir_ty/src/tests/traits.rs
2020-09-10 20:01:23 +08:00

3154 lines
70 KiB
Rust

use expect_test::expect;
use test_utils::mark;
use super::{check_infer, check_infer_with_mismatches, check_types};
#[test]
fn infer_await() {
check_types(
r#"
//- /main.rs crate:main deps:core
struct IntFuture;
impl Future for IntFuture {
type Output = u64;
}
fn test() {
let r = IntFuture;
let v = r.await;
v;
} //^ u64
//- /core.rs crate:core
#[prelude_import] use future::*;
mod future {
#[lang = "future_trait"]
trait Future {
type Output;
}
}
"#,
);
}
#[test]
fn infer_async() {
check_types(
r#"
//- /main.rs crate:main deps:core
async fn foo() -> u64 {
128
}
fn test() {
let r = foo();
let v = r.await;
v;
} //^ u64
//- /core.rs crate:core
#[prelude_import] use future::*;
mod future {
#[lang = "future_trait"]
trait Future {
type Output;
}
}
"#,
);
}
#[test]
fn infer_desugar_async() {
check_types(
r#"
//- /main.rs crate:main deps:core
async fn foo() -> u64 {
128
}
fn test() {
let r = foo();
r;
} //^ impl Future<Output = u64>
//- /core.rs crate:core
#[prelude_import] use future::*;
mod future {
trait Future {
type Output;
}
}
"#,
);
}
#[test]
fn infer_async_block() {
check_types(
r#"
//- /main.rs crate:main deps:core
async fn test() {
let a = async { 42 };
a;
// ^ impl Future<Output = i32>
let x = a.await;
x;
// ^ i32
let b = async {}.await;
b;
// ^ ()
let c = async {
let y = Option::None;
y
// ^ Option<u64>
};
let _: Option<u64> = c.await;
c;
// ^ impl Future<Output = Option<u64>>
}
enum Option<T> { None, Some(T) }
//- /core.rs crate:core
#[prelude_import] use future::*;
mod future {
#[lang = "future_trait"]
trait Future {
type Output;
}
}
"#,
);
}
#[test]
fn infer_try() {
check_types(
r#"
//- /main.rs crate:main deps:core
fn test() {
let r: Result<i32, u64> = Result::Ok(1);
let v = r?;
v;
} //^ i32
//- /core.rs crate:core
#[prelude_import] use ops::*;
mod ops {
trait Try {
type Ok;
type Error;
}
}
#[prelude_import] use result::*;
mod result {
enum Result<O, E> {
Ok(O),
Err(E)
}
impl<O, E> crate::ops::Try for Result<O, E> {
type Ok = O;
type Error = E;
}
}
"#,
);
}
#[test]
fn infer_for_loop() {
check_types(
r#"
//- /main.rs crate:main deps:core,alloc
use alloc::collections::Vec;
fn test() {
let v = Vec::new();
v.push("foo");
for x in v {
x;
} //^ &str
}
//- /core.rs crate:core
#[prelude_import] use iter::*;
mod iter {
trait IntoIterator {
type Item;
}
}
//- /alloc.rs crate:alloc deps:core
mod collections {
struct Vec<T> {}
impl<T> Vec<T> {
fn new() -> Self { Vec {} }
fn push(&mut self, t: T) { }
}
impl<T> IntoIterator for Vec<T> {
type Item=T;
}
}
"#,
);
}
#[test]
fn infer_ops_neg() {
check_types(
r#"
//- /main.rs crate:main deps:std
struct Bar;
struct Foo;
impl std::ops::Neg for Bar {
type Output = Foo;
}
fn test() {
let a = Bar;
let b = -a;
b;
} //^ Foo
//- /std.rs crate:std
#[prelude_import] use ops::*;
mod ops {
#[lang = "neg"]
pub trait Neg {
type Output;
}
}
"#,
);
}
#[test]
fn infer_ops_not() {
check_types(
r#"
//- /main.rs crate:main deps:std
struct Bar;
struct Foo;
impl std::ops::Not for Bar {
type Output = Foo;
}
fn test() {
let a = Bar;
let b = !a;
b;
} //^ Foo
//- /std.rs crate:std
#[prelude_import] use ops::*;
mod ops {
#[lang = "not"]
pub trait Not {
type Output;
}
}
"#,
);
}
#[test]
fn infer_from_bound_1() {
check_infer(
r#"
trait Trait<T> {}
struct S<T>(T);
impl<U> Trait<U> for S<U> {}
fn foo<T: Trait<u32>>(t: T) {}
fn test() {
let s = S(unknown);
foo(s);
}
"#,
expect![[r#"
85..86 't': T
91..93 '{}': ()
104..143 '{ ...(s); }': ()
114..115 's': S<u32>
118..119 'S': S<u32>(u32) -> S<u32>
118..128 'S(unknown)': S<u32>
120..127 'unknown': u32
134..137 'foo': fn foo<S<u32>>(S<u32>)
134..140 'foo(s)': ()
138..139 's': S<u32>
"#]],
);
}
#[test]
fn infer_from_bound_2() {
check_infer(
r#"
trait Trait<T> {}
struct S<T>(T);
impl<U> Trait<U> for S<U> {}
fn foo<U, T: Trait<U>>(t: T) -> U {}
fn test() {
let s = S(unknown);
let x: u32 = foo(s);
}
"#,
expect![[r#"
86..87 't': T
97..99 '{}': ()
110..162 '{ ...(s); }': ()
120..121 's': S<u32>
124..125 'S': S<u32>(u32) -> S<u32>
124..134 'S(unknown)': S<u32>
126..133 'unknown': u32
144..145 'x': u32
153..156 'foo': fn foo<u32, S<u32>>(S<u32>) -> u32
153..159 'foo(s)': u32
157..158 's': S<u32>
"#]],
);
}
#[test]
fn trait_default_method_self_bound_implements_trait() {
mark::check!(trait_self_implements_self);
check_infer(
r#"
trait Trait {
fn foo(&self) -> i64;
fn bar(&self) -> {
let x = self.foo();
}
}
"#,
expect![[r#"
26..30 'self': &Self
52..56 'self': &Self
61..96 '{ ... }': ()
75..76 'x': i64
79..83 'self': &Self
79..89 'self.foo()': i64
"#]],
);
}
#[test]
fn trait_default_method_self_bound_implements_super_trait() {
check_infer(
r#"
trait SuperTrait {
fn foo(&self) -> i64;
}
trait Trait: SuperTrait {
fn bar(&self) -> {
let x = self.foo();
}
}
"#,
expect![[r#"
31..35 'self': &Self
85..89 'self': &Self
94..129 '{ ... }': ()
108..109 'x': i64
112..116 'self': &Self
112..122 'self.foo()': i64
"#]],
);
}
#[test]
fn infer_project_associated_type() {
check_infer(
r#"
trait Iterable {
type Item;
}
struct S;
impl Iterable for S { type Item = u32; }
fn test<T: Iterable>() {
let x: <S as Iterable>::Item = 1;
let y: <T as Iterable>::Item = no_matter;
let z: T::Item = no_matter;
let a: <T>::Item = no_matter;
}
"#,
expect![[r#"
108..261 '{ ...ter; }': ()
118..119 'x': u32
145..146 '1': u32
156..157 'y': Iterable::Item<T>
183..192 'no_matter': Iterable::Item<T>
202..203 'z': Iterable::Item<T>
215..224 'no_matter': Iterable::Item<T>
234..235 'a': Iterable::Item<T>
249..258 'no_matter': Iterable::Item<T>
"#]],
);
}
#[test]
fn infer_return_associated_type() {
check_infer(
r#"
trait Iterable {
type Item;
}
struct S;
impl Iterable for S { type Item = u32; }
fn foo1<T: Iterable>(t: T) -> T::Item {}
fn foo2<T: Iterable>(t: T) -> <T as Iterable>::Item {}
fn foo3<T: Iterable>(t: T) -> <T>::Item {}
fn test() {
let x = foo1(S);
let y = foo2(S);
let z = foo3(S);
}
"#,
expect![[r#"
106..107 't': T
123..125 '{}': ()
147..148 't': T
178..180 '{}': ()
202..203 't': T
221..223 '{}': ()
234..300 '{ ...(S); }': ()
244..245 'x': u32
248..252 'foo1': fn foo1<S>(S) -> <S as Iterable>::Item
248..255 'foo1(S)': u32
253..254 'S': S
265..266 'y': u32
269..273 'foo2': fn foo2<S>(S) -> <S as Iterable>::Item
269..276 'foo2(S)': u32
274..275 'S': S
286..287 'z': u32
290..294 'foo3': fn foo3<S>(S) -> <S as Iterable>::Item
290..297 'foo3(S)': u32
295..296 'S': S
"#]],
);
}
#[test]
fn infer_associated_type_bound() {
check_infer(
r#"
trait Iterable {
type Item;
}
fn test<T: Iterable<Item=u32>>() {
let y: T::Item = unknown;
}
"#,
expect![[r#"
67..100 '{ ...own; }': ()
77..78 'y': u32
90..97 'unknown': u32
"#]],
);
}
#[test]
fn infer_const_body() {
check_infer(
r#"
const A: u32 = 1 + 1;
static B: u64 = { let x = 1; x };
"#,
expect![[r#"
15..16 '1': u32
15..20 '1 + 1': u32
19..20 '1': u32
38..54 '{ let ...1; x }': u64
44..45 'x': u64
48..49 '1': u64
51..52 'x': u64
"#]],
);
}
#[test]
fn tuple_struct_fields() {
check_infer(
r#"
struct S(i32, u64);
fn test() -> u64 {
let a = S(4, 6);
let b = a.0;
a.1
}
"#,
expect![[r#"
37..86 '{ ... a.1 }': u64
47..48 'a': S
51..52 'S': S(i32, u64) -> S
51..58 'S(4, 6)': S
53..54 '4': i32
56..57 '6': u64
68..69 'b': i32
72..73 'a': S
72..75 'a.0': i32
81..82 'a': S
81..84 'a.1': u64
"#]],
);
}
#[test]
fn tuple_struct_with_fn() {
check_infer(
r#"
struct S(fn(u32) -> u64);
fn test() -> u64 {
let a = S(|i| 2*i);
let b = a.0(4);
a.0(2)
}
"#,
expect![[r#"
43..101 '{ ...0(2) }': u64
53..54 'a': S
57..58 'S': S(fn(u32) -> u64) -> S
57..67 'S(|i| 2*i)': S
59..66 '|i| 2*i': |u32| -> u64
60..61 'i': u32
63..64 '2': u32
63..66 '2*i': u32
65..66 'i': u32
77..78 'b': u64
81..82 'a': S
81..84 'a.0': fn(u32) -> u64
81..87 'a.0(4)': u64
85..86 '4': u32
93..94 'a': S
93..96 'a.0': fn(u32) -> u64
93..99 'a.0(2)': u64
97..98 '2': u32
"#]],
);
}
#[test]
fn indexing_arrays() {
check_infer(
"fn main() { &mut [9][2]; }",
expect![[r#"
10..26 '{ &mut...[2]; }': ()
12..23 '&mut [9][2]': &mut {unknown}
17..20 '[9]': [i32; _]
17..23 '[9][2]': {unknown}
18..19 '9': i32
21..22 '2': i32
"#]],
)
}
#[test]
fn infer_ops_index() {
check_types(
r#"
//- /main.rs crate:main deps:std
struct Bar;
struct Foo;
impl std::ops::Index<u32> for Bar {
type Output = Foo;
}
fn test() {
let a = Bar;
let b = a[1u32];
b;
} //^ Foo
//- /std.rs crate:std
#[prelude_import] use ops::*;
mod ops {
#[lang = "index"]
pub trait Index<Idx> {
type Output;
}
}
"#,
);
}
#[test]
fn infer_ops_index_int() {
check_types(
r#"
//- /main.rs crate:main deps:std
struct Bar;
struct Foo;
impl std::ops::Index<u32> for Bar {
type Output = Foo;
}
struct Range;
impl std::ops::Index<Range> for Bar {
type Output = Bar;
}
fn test() {
let a = Bar;
let b = a[1];
b;
//^ Foo
}
//- /std.rs crate:std
#[prelude_import] use ops::*;
mod ops {
#[lang = "index"]
pub trait Index<Idx> {
type Output;
}
}
"#,
);
}
#[test]
fn infer_ops_index_autoderef() {
check_types(
r#"
//- /main.rs crate:main deps:std
fn test() {
let a = &[1u32, 2, 3];
let b = a[1u32];
b;
} //^ u32
//- /std.rs crate:std
impl<T> ops::Index<u32> for [T] {
type Output = T;
}
#[prelude_import] use ops::*;
mod ops {
#[lang = "index"]
pub trait Index<Idx> {
type Output;
}
}
"#,
);
}
#[test]
fn deref_trait() {
check_types(
r#"
#[lang = "deref"]
trait Deref {
type Target;
fn deref(&self) -> &Self::Target;
}
struct Arc<T>;
impl<T> Deref for Arc<T> {
type Target = T;
}
struct S;
impl S {
fn foo(&self) -> u128 {}
}
fn test(s: Arc<S>) {
(*s, s.foo());
} //^ (S, u128)
"#,
);
}
#[test]
fn deref_trait_with_inference_var() {
check_types(
r#"
//- /main.rs
#[lang = "deref"]
trait Deref {
type Target;
fn deref(&self) -> &Self::Target;
}
struct Arc<T>;
fn new_arc<T>() -> Arc<T> {}
impl<T> Deref for Arc<T> {
type Target = T;
}
struct S;
fn foo(a: Arc<S>) {}
fn test() {
let a = new_arc();
let b = (*a);
//^ S
foo(a);
}
"#,
);
}
#[test]
fn deref_trait_infinite_recursion() {
check_types(
r#"
#[lang = "deref"]
trait Deref {
type Target;
fn deref(&self) -> &Self::Target;
}
struct S;
impl Deref for S {
type Target = S;
}
fn test(s: S) {
s.foo();
} //^ {unknown}
"#,
);
}
#[test]
fn deref_trait_with_question_mark_size() {
check_types(
r#"
#[lang = "deref"]
trait Deref {
type Target;
fn deref(&self) -> &Self::Target;
}
struct Arc<T>;
impl<T> Deref for Arc<T> {
type Target = T;
}
struct S;
impl S {
fn foo(&self) -> u128 {}
}
fn test(s: Arc<S>) {
(*s, s.foo());
} //^ (S, u128)
"#,
);
}
#[test]
fn obligation_from_function_clause() {
check_types(
r#"
struct S;
trait Trait<T> {}
impl Trait<u32> for S {}
fn foo<T: Trait<U>, U>(t: T) -> U {}
fn test(s: S) {
(foo(s));
} //^ u32
"#,
);
}
#[test]
fn obligation_from_method_clause() {
check_types(
r#"
//- /main.rs
struct S;
trait Trait<T> {}
impl Trait<isize> for S {}
struct O;
impl O {
fn foo<T: Trait<U>, U>(&self, t: T) -> U {}
}
fn test() {
O.foo(S);
} //^ isize
"#,
);
}
#[test]
fn obligation_from_self_method_clause() {
check_types(
r#"
struct S;
trait Trait<T> {}
impl Trait<i64> for S {}
impl S {
fn foo<U>(&self) -> U where Self: Trait<U> {}
}
fn test() {
S.foo();
} //^ i64
"#,
);
}
#[test]
fn obligation_from_impl_clause() {
check_types(
r#"
struct S;
trait Trait<T> {}
impl Trait<&str> for S {}
struct O<T>;
impl<U, T: Trait<U>> O<T> {
fn foo(&self) -> U {}
}
fn test(o: O<S>) {
o.foo();
} //^ &str
"#,
);
}
#[test]
fn generic_param_env_1() {
check_types(
r#"
trait Clone {}
trait Trait { fn foo(self) -> u128; }
struct S;
impl Clone for S {}
impl<T> Trait for T where T: Clone {}
fn test<T: Clone>(t: T) { t.foo(); }
//^ u128
"#,
);
}
#[test]
fn generic_param_env_1_not_met() {
check_types(
r#"
//- /main.rs
trait Clone {}
trait Trait { fn foo(self) -> u128; }
struct S;
impl Clone for S {}
impl<T> Trait for T where T: Clone {}
fn test<T>(t: T) { t.foo(); }
//^ {unknown}
"#,
);
}
#[test]
fn generic_param_env_2() {
check_types(
r#"
trait Trait { fn foo(self) -> u128; }
struct S;
impl Trait for S {}
fn test<T: Trait>(t: T) { t.foo(); }
//^ u128
"#,
);
}
#[test]
fn generic_param_env_2_not_met() {
check_types(
r#"
trait Trait { fn foo(self) -> u128; }
struct S;
impl Trait for S {}
fn test<T>(t: T) { t.foo(); }
//^ {unknown}
"#,
);
}
#[test]
fn generic_param_env_deref() {
check_types(
r#"
#[lang = "deref"]
trait Deref {
type Target;
}
trait Trait {}
impl<T> Deref for T where T: Trait {
type Target = i128;
}
fn test<T: Trait>(t: T) { (*t); }
//^ i128
"#,
);
}
#[test]
fn associated_type_placeholder() {
// inside the generic function, the associated type gets normalized to a placeholder `ApplL::Out<T>` [https://rust-lang.github.io/rustc-guide/traits/associated-types.html#placeholder-associated-types].
check_types(
r#"
pub trait ApplyL {
type Out;
}
pub struct RefMutL<T>;
impl<T> ApplyL for RefMutL<T> {
type Out = <T as ApplyL>::Out;
}
fn test<T: ApplyL>() {
let y: <RefMutL<T> as ApplyL>::Out = no_matter;
y;
} //^ ApplyL::Out<T>
"#,
);
}
#[test]
fn associated_type_placeholder_2() {
check_types(
r#"
pub trait ApplyL {
type Out;
}
fn foo<T: ApplyL>(t: T) -> <T as ApplyL>::Out;
fn test<T: ApplyL>(t: T) {
let y = foo(t);
y;
} //^ ApplyL::Out<T>
"#,
);
}
#[test]
fn argument_impl_trait() {
check_infer_with_mismatches(
r#"
trait Trait<T> {
fn foo(&self) -> T;
fn foo2(&self) -> i64;
}
fn bar(x: impl Trait<u16>) {}
struct S<T>(T);
impl<T> Trait<T> for S<T> {}
fn test(x: impl Trait<u64>, y: &impl Trait<u32>) {
x;
y;
let z = S(1);
bar(z);
x.foo();
y.foo();
z.foo();
x.foo2();
y.foo2();
z.foo2();
}
"#,
expect![[r#"
29..33 'self': &Self
54..58 'self': &Self
77..78 'x': impl Trait<u16>
97..99 '{}': ()
154..155 'x': impl Trait<u64>
174..175 'y': &impl Trait<u32>
195..323 '{ ...2(); }': ()
201..202 'x': impl Trait<u64>
208..209 'y': &impl Trait<u32>
219..220 'z': S<u16>
223..224 'S': S<u16>(u16) -> S<u16>
223..227 'S(1)': S<u16>
225..226 '1': u16
233..236 'bar': fn bar(S<u16>)
233..239 'bar(z)': ()
237..238 'z': S<u16>
245..246 'x': impl Trait<u64>
245..252 'x.foo()': u64
258..259 'y': &impl Trait<u32>
258..265 'y.foo()': u32
271..272 'z': S<u16>
271..278 'z.foo()': u16
284..285 'x': impl Trait<u64>
284..292 'x.foo2()': i64
298..299 'y': &impl Trait<u32>
298..306 'y.foo2()': i64
312..313 'z': S<u16>
312..320 'z.foo2()': i64
"#]],
);
}
#[test]
fn argument_impl_trait_type_args_1() {
check_infer_with_mismatches(
r#"
trait Trait {}
trait Foo {
// this function has an implicit Self param, an explicit type param,
// and an implicit impl Trait param!
fn bar<T>(x: impl Trait) -> T { loop {} }
}
fn foo<T>(x: impl Trait) -> T { loop {} }
struct S;
impl Trait for S {}
struct F;
impl Foo for F {}
fn test() {
Foo::bar(S);
<F as Foo>::bar(S);
F::bar(S);
Foo::bar::<u32>(S);
<F as Foo>::bar::<u32>(S);
foo(S);
foo::<u32>(S);
foo::<u32, i32>(S); // we should ignore the extraneous i32
}
"#,
expect![[r#"
155..156 'x': impl Trait
175..186 '{ loop {} }': T
177..184 'loop {}': !
182..184 '{}': ()
199..200 'x': impl Trait
219..230 '{ loop {} }': T
221..228 'loop {}': !
226..228 '{}': ()
300..509 '{ ... i32 }': ()
306..314 'Foo::bar': fn bar<{unknown}, {unknown}>(S) -> {unknown}
306..317 'Foo::bar(S)': {unknown}
315..316 'S': S
323..338 '<F as Foo>::bar': fn bar<F, {unknown}>(S) -> {unknown}
323..341 '<F as ...bar(S)': {unknown}
339..340 'S': S
347..353 'F::bar': fn bar<F, {unknown}>(S) -> {unknown}
347..356 'F::bar(S)': {unknown}
354..355 'S': S
362..377 'Foo::bar::<u32>': fn bar<{unknown}, u32>(S) -> u32
362..380 'Foo::b...32>(S)': u32
378..379 'S': S
386..408 '<F as ...:<u32>': fn bar<F, u32>(S) -> u32
386..411 '<F as ...32>(S)': u32
409..410 'S': S
418..421 'foo': fn foo<{unknown}>(S) -> {unknown}
418..424 'foo(S)': {unknown}
422..423 'S': S
430..440 'foo::<u32>': fn foo<u32>(S) -> u32
430..443 'foo::<u32>(S)': u32
441..442 'S': S
449..464 'foo::<u32, i32>': fn foo<u32>(S) -> u32
449..467 'foo::<...32>(S)': u32
465..466 'S': S
"#]],
);
}
#[test]
fn argument_impl_trait_type_args_2() {
check_infer_with_mismatches(
r#"
trait Trait {}
struct S;
impl Trait for S {}
struct F<T>;
impl<T> F<T> {
fn foo<U>(self, x: impl Trait) -> (T, U) { loop {} }
}
fn test() {
F.foo(S);
F::<u32>.foo(S);
F::<u32>.foo::<i32>(S);
F::<u32>.foo::<i32, u32>(S); // extraneous argument should be ignored
}
"#,
expect![[r#"
87..91 'self': F<T>
93..94 'x': impl Trait
118..129 '{ loop {} }': (T, U)
120..127 'loop {}': !
125..127 '{}': ()
143..283 '{ ...ored }': ()
149..150 'F': F<{unknown}>
149..157 'F.foo(S)': ({unknown}, {unknown})
155..156 'S': S
163..171 'F::<u32>': F<u32>
163..178 'F::<u32>.foo(S)': (u32, {unknown})
176..177 'S': S
184..192 'F::<u32>': F<u32>
184..206 'F::<u3...32>(S)': (u32, i32)
204..205 'S': S
212..220 'F::<u32>': F<u32>
212..239 'F::<u3...32>(S)': (u32, i32)
237..238 'S': S
"#]],
);
}
#[test]
fn argument_impl_trait_to_fn_pointer() {
check_infer_with_mismatches(
r#"
trait Trait {}
fn foo(x: impl Trait) { loop {} }
struct S;
impl Trait for S {}
fn test() {
let f: fn(S) -> () = foo;
}
"#,
expect![[r#"
22..23 'x': impl Trait
37..48 '{ loop {} }': ()
39..46 'loop {}': !
44..46 '{}': ()
90..123 '{ ...foo; }': ()
100..101 'f': fn(S)
117..120 'foo': fn foo(S)
"#]],
);
}
#[test]
fn impl_trait() {
check_infer(
r#"
trait Trait<T> {
fn foo(&self) -> T;
fn foo2(&self) -> i64;
}
fn bar() -> impl Trait<u64> {}
fn test(x: impl Trait<u64>, y: &impl Trait<u64>) {
x;
y;
let z = bar();
x.foo();
y.foo();
z.foo();
x.foo2();
y.foo2();
z.foo2();
}
"#,
expect![[r#"
29..33 'self': &Self
54..58 'self': &Self
98..100 '{}': ()
110..111 'x': impl Trait<u64>
130..131 'y': &impl Trait<u64>
151..268 '{ ...2(); }': ()
157..158 'x': impl Trait<u64>
164..165 'y': &impl Trait<u64>
175..176 'z': impl Trait<u64>
179..182 'bar': fn bar() -> impl Trait<u64>
179..184 'bar()': impl Trait<u64>
190..191 'x': impl Trait<u64>
190..197 'x.foo()': u64
203..204 'y': &impl Trait<u64>
203..210 'y.foo()': u64
216..217 'z': impl Trait<u64>
216..223 'z.foo()': u64
229..230 'x': impl Trait<u64>
229..237 'x.foo2()': i64
243..244 'y': &impl Trait<u64>
243..251 'y.foo2()': i64
257..258 'z': impl Trait<u64>
257..265 'z.foo2()': i64
"#]],
);
}
#[test]
fn simple_return_pos_impl_trait() {
mark::check!(lower_rpit);
check_infer(
r#"
trait Trait<T> {
fn foo(&self) -> T;
}
fn bar() -> impl Trait<u64> { loop {} }
fn test() {
let a = bar();
a.foo();
}
"#,
expect![[r#"
29..33 'self': &Self
71..82 '{ loop {} }': !
73..80 'loop {}': !
78..80 '{}': ()
94..129 '{ ...o(); }': ()
104..105 'a': impl Trait<u64>
108..111 'bar': fn bar() -> impl Trait<u64>
108..113 'bar()': impl Trait<u64>
119..120 'a': impl Trait<u64>
119..126 'a.foo()': u64
"#]],
);
}
#[test]
fn more_return_pos_impl_trait() {
check_infer(
r#"
trait Iterator {
type Item;
fn next(&mut self) -> Self::Item;
}
trait Trait<T> {
fn foo(&self) -> T;
}
fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>) { loop {} }
fn baz<T>(t: T) -> (impl Iterator<Item = impl Trait<T>>, impl Trait<T>) { loop {} }
fn test() {
let (a, b) = bar();
a.next().foo();
b.foo();
let (c, d) = baz(1u128);
c.next().foo();
d.foo();
}
"#,
expect![[r#"
49..53 'self': &mut Self
101..105 'self': &Self
184..195 '{ loop {} }': ({unknown}, {unknown})
186..193 'loop {}': !
191..193 '{}': ()
206..207 't': T
268..279 '{ loop {} }': ({unknown}, {unknown})
270..277 'loop {}': !
275..277 '{}': ()
291..413 '{ ...o(); }': ()
301..307 '(a, b)': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
302..303 'a': impl Iterator<Item = impl Trait<u32>>
305..306 'b': impl Trait<u64>
310..313 'bar': fn bar() -> (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
310..315 'bar()': (impl Iterator<Item = impl Trait<u32>>, impl Trait<u64>)
321..322 'a': impl Iterator<Item = impl Trait<u32>>
321..329 'a.next()': impl Trait<u32>
321..335 'a.next().foo()': u32
341..342 'b': impl Trait<u64>
341..348 'b.foo()': u64
358..364 '(c, d)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
359..360 'c': impl Iterator<Item = impl Trait<u128>>
362..363 'd': impl Trait<u128>
367..370 'baz': fn baz<u128>(u128) -> (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
367..377 'baz(1u128)': (impl Iterator<Item = impl Trait<u128>>, impl Trait<u128>)
371..376 '1u128': u128
383..384 'c': impl Iterator<Item = impl Trait<u128>>
383..391 'c.next()': impl Trait<u128>
383..397 'c.next().foo()': u128
403..404 'd': impl Trait<u128>
403..410 'd.foo()': u128
"#]],
);
}
#[test]
fn dyn_trait() {
check_infer(
r#"
trait Trait<T> {
fn foo(&self) -> T;
fn foo2(&self) -> i64;
}
fn bar() -> dyn Trait<u64> {}
fn test(x: dyn Trait<u64>, y: &dyn Trait<u64>) {
x;
y;
let z = bar();
x.foo();
y.foo();
z.foo();
x.foo2();
y.foo2();
z.foo2();
}
"#,
expect![[r#"
29..33 'self': &Self
54..58 'self': &Self
97..99 '{}': ()
109..110 'x': dyn Trait<u64>
128..129 'y': &dyn Trait<u64>
148..265 '{ ...2(); }': ()
154..155 'x': dyn Trait<u64>
161..162 'y': &dyn Trait<u64>
172..173 'z': dyn Trait<u64>
176..179 'bar': fn bar() -> dyn Trait<u64>
176..181 'bar()': dyn Trait<u64>
187..188 'x': dyn Trait<u64>
187..194 'x.foo()': u64
200..201 'y': &dyn Trait<u64>
200..207 'y.foo()': u64
213..214 'z': dyn Trait<u64>
213..220 'z.foo()': u64
226..227 'x': dyn Trait<u64>
226..234 'x.foo2()': i64
240..241 'y': &dyn Trait<u64>
240..248 'y.foo2()': i64
254..255 'z': dyn Trait<u64>
254..262 'z.foo2()': i64
"#]],
);
}
#[test]
fn dyn_trait_in_impl() {
check_infer(
r#"
trait Trait<T, U> {
fn foo(&self) -> (T, U);
}
struct S<T, U> {}
impl<T, U> S<T, U> {
fn bar(&self) -> &dyn Trait<T, U> { loop {} }
}
trait Trait2<T, U> {
fn baz(&self) -> (T, U);
}
impl<T, U> Trait2<T, U> for dyn Trait<T, U> { }
fn test(s: S<u32, i32>) {
s.bar().baz();
}
"#,
expect![[r#"
32..36 'self': &Self
102..106 'self': &S<T, U>
128..139 '{ loop {} }': &dyn Trait<T, U>
130..137 'loop {}': !
135..137 '{}': ()
175..179 'self': &Self
251..252 's': S<u32, i32>
267..289 '{ ...z(); }': ()
273..274 's': S<u32, i32>
273..280 's.bar()': &dyn Trait<u32, i32>
273..286 's.bar().baz()': (u32, i32)
"#]],
);
}
#[test]
fn dyn_trait_bare() {
check_infer(
r#"
trait Trait {
fn foo(&self) -> u64;
}
fn bar() -> Trait {}
fn test(x: Trait, y: &Trait) -> u64 {
x;
y;
let z = bar();
x.foo();
y.foo();
z.foo();
}
"#,
expect![[r#"
26..30 'self': &Self
60..62 '{}': ()
72..73 'x': dyn Trait
82..83 'y': &dyn Trait
100..175 '{ ...o(); }': ()
106..107 'x': dyn Trait
113..114 'y': &dyn Trait
124..125 'z': dyn Trait
128..131 'bar': fn bar() -> dyn Trait
128..133 'bar()': dyn Trait
139..140 'x': dyn Trait
139..146 'x.foo()': u64
152..153 'y': &dyn Trait
152..159 'y.foo()': u64
165..166 'z': dyn Trait
165..172 'z.foo()': u64
"#]],
);
}
#[test]
fn weird_bounds() {
check_infer(
r#"
trait Trait {}
fn test(a: impl Trait + 'lifetime, b: impl 'lifetime, c: impl (Trait), d: impl ('lifetime), e: impl ?Sized, f: impl Trait + ?Sized) {}
"#,
expect![[r#"
23..24 'a': impl Trait + {error}
50..51 'b': impl {error}
69..70 'c': impl Trait
86..87 'd': impl {error}
107..108 'e': impl {error}
123..124 'f': impl Trait + {error}
147..149 '{}': ()
"#]],
);
}
#[test]
#[ignore]
fn error_bound_chalk() {
check_types(
r#"
trait Trait {
fn foo(&self) -> u32 {}
}
fn test(x: (impl Trait + UnknownTrait)) {
x.foo();
} //^ u32
"#,
);
}
#[test]
fn assoc_type_bindings() {
check_infer(
r#"
trait Trait {
type Type;
}
fn get<T: Trait>(t: T) -> <T as Trait>::Type {}
fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
fn set<T: Trait<Type = u64>>(t: T) -> T {t}
struct S<T>;
impl<T> Trait for S<T> { type Type = T; }
fn test<T: Trait<Type = u32>>(x: T, y: impl Trait<Type = i64>) {
get(x);
get2(x);
get(y);
get2(y);
get(set(S));
get2(set(S));
get2(S::<str>);
}
"#,
expect![[r#"
49..50 't': T
77..79 '{}': ()
111..112 't': T
122..124 '{}': ()
154..155 't': T
165..168 '{t}': T
166..167 't': T
256..257 'x': T
262..263 'y': impl Trait<Type = i64>
289..397 '{ ...r>); }': ()
295..298 'get': fn get<T>(T) -> <T as Trait>::Type
295..301 'get(x)': u32
299..300 'x': T
307..311 'get2': fn get2<u32, T>(T) -> u32
307..314 'get2(x)': u32
312..313 'x': T
320..323 'get': fn get<impl Trait<Type = i64>>(impl Trait<Type = i64>) -> <impl Trait<Type = i64> as Trait>::Type
320..326 'get(y)': i64
324..325 'y': impl Trait<Type = i64>
332..336 'get2': fn get2<i64, impl Trait<Type = i64>>(impl Trait<Type = i64>) -> i64
332..339 'get2(y)': i64
337..338 'y': impl Trait<Type = i64>
345..348 'get': fn get<S<u64>>(S<u64>) -> <S<u64> as Trait>::Type
345..356 'get(set(S))': u64
349..352 'set': fn set<S<u64>>(S<u64>) -> S<u64>
349..355 'set(S)': S<u64>
353..354 'S': S<u64>
362..366 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
362..374 'get2(set(S))': u64
367..370 'set': fn set<S<u64>>(S<u64>) -> S<u64>
367..373 'set(S)': S<u64>
371..372 'S': S<u64>
380..384 'get2': fn get2<str, S<str>>(S<str>) -> str
380..394 'get2(S::<str>)': str
385..393 'S::<str>': S<str>
"#]],
);
}
#[test]
fn impl_trait_assoc_binding_projection_bug() {
check_types(
r#"
//- /main.rs crate:main deps:std
pub trait Language {
type Kind;
}
pub enum RustLanguage {}
impl Language for RustLanguage {
type Kind = SyntaxKind;
}
struct SyntaxNode<L> {}
fn foo() -> impl Iterator<Item = SyntaxNode<RustLanguage>> {}
trait Clone {
fn clone(&self) -> Self;
}
fn api_walkthrough() {
for node in foo() {
node.clone();
} //^ {unknown}
}
//- /std.rs crate:std
#[prelude_import] use iter::*;
mod iter {
trait IntoIterator {
type Item;
}
trait Iterator {
type Item;
}
impl<T: Iterator> IntoIterator for T {
type Item = <T as Iterator>::Item;
}
}
"#,
);
}
#[test]
fn projection_eq_within_chalk() {
check_infer(
r#"
trait Trait1 {
type Type;
}
trait Trait2<T> {
fn foo(self) -> T;
}
impl<T, U> Trait2<T> for U where U: Trait1<Type = T> {}
fn test<T: Trait1<Type = u32>>(x: T) {
x.foo();
}
"#,
expect![[r#"
61..65 'self': Self
163..164 'x': T
169..185 '{ ...o(); }': ()
175..176 'x': T
175..182 'x.foo()': u32
"#]],
);
}
#[test]
fn where_clause_trait_in_scope_for_method_resolution() {
check_types(
r#"
mod foo {
trait Trait {
fn foo(&self) -> u32 {}
}
}
fn test<T: foo::Trait>(x: T) {
x.foo();
} //^ u32
"#,
);
}
#[test]
fn super_trait_method_resolution() {
check_infer(
r#"
mod foo {
trait SuperTrait {
fn foo(&self) -> u32 {}
}
}
trait Trait1: foo::SuperTrait {}
trait Trait2 where Self: foo::SuperTrait {}
fn test<T: Trait1, U: Trait2>(x: T, y: U) {
x.foo();
y.foo();
}
"#,
expect![[r#"
49..53 'self': &Self
62..64 '{}': ()
181..182 'x': T
187..188 'y': U
193..222 '{ ...o(); }': ()
199..200 'x': T
199..206 'x.foo()': u32
212..213 'y': U
212..219 'y.foo()': u32
"#]],
);
}
#[test]
fn super_trait_impl_trait_method_resolution() {
check_infer(
r#"
mod foo {
trait SuperTrait {
fn foo(&self) -> u32 {}
}
}
trait Trait1: foo::SuperTrait {}
fn test(x: &impl Trait1) {
x.foo();
}
"#,
expect![[r#"
49..53 'self': &Self
62..64 '{}': ()
115..116 'x': &impl Trait1
132..148 '{ ...o(); }': ()
138..139 'x': &impl Trait1
138..145 'x.foo()': u32
"#]],
);
}
#[test]
fn super_trait_cycle() {
// This just needs to not crash
check_infer(
r#"
trait A: B {}
trait B: A {}
fn test<T: A>(x: T) {
x.foo();
}
"#,
expect![[r#"
43..44 'x': T
49..65 '{ ...o(); }': ()
55..56 'x': T
55..62 'x.foo()': {unknown}
"#]],
);
}
#[test]
fn super_trait_assoc_type_bounds() {
check_infer(
r#"
trait SuperTrait { type Type; }
trait Trait where Self: SuperTrait {}
fn get2<U, T: Trait<Type = U>>(t: T) -> U {}
fn set<T: Trait<Type = u64>>(t: T) -> T {t}
struct S<T>;
impl<T> SuperTrait for S<T> { type Type = T; }
impl<T> Trait for S<T> {}
fn test() {
get2(set(S));
}
"#,
expect![[r#"
102..103 't': T
113..115 '{}': ()
145..146 't': T
156..159 '{t}': T
157..158 't': T
258..279 '{ ...S)); }': ()
264..268 'get2': fn get2<u64, S<u64>>(S<u64>) -> u64
264..276 'get2(set(S))': u64
269..272 'set': fn set<S<u64>>(S<u64>) -> S<u64>
269..275 'set(S)': S<u64>
273..274 'S': S<u64>
"#]],
);
}
#[test]
fn fn_trait() {
check_infer(
r#"
trait FnOnce<Args> {
type Output;
fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
}
fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
f.call_once((1, 2));
}
"#,
expect![[r#"
56..60 'self': Self
62..66 'args': Args
149..150 'f': F
155..183 '{ ...2)); }': ()
161..162 'f': F
161..180 'f.call...1, 2))': u128
173..179 '(1, 2)': (u32, u64)
174..175 '1': u32
177..178 '2': u64
"#]],
);
}
#[test]
fn fn_ptr_and_item() {
check_infer(
r#"
#[lang="fn_once"]
trait FnOnce<Args> {
type Output;
fn call_once(self, args: Args) -> Self::Output;
}
trait Foo<T> {
fn foo(&self) -> T;
}
struct Bar<T>(T);
impl<A1, R, F: FnOnce(A1) -> R> Foo<(A1, R)> for Bar<F> {
fn foo(&self) -> (A1, R) {}
}
enum Opt<T> { None, Some(T) }
impl<T> Opt<T> {
fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Opt<U> {}
}
fn test() {
let bar: Bar<fn(u8) -> u32>;
bar.foo();
let opt: Opt<u8>;
let f: fn(u8) -> u32;
opt.map(f);
}
"#,
expect![[r#"
74..78 'self': Self
80..84 'args': Args
139..143 'self': &Self
243..247 'self': &Bar<F>
260..262 '{}': ()
346..350 'self': Opt<T>
352..353 'f': F
368..370 '{}': ()
384..500 '{ ...(f); }': ()
394..397 'bar': Bar<fn(u8) -> u32>
423..426 'bar': Bar<fn(u8) -> u32>
423..432 'bar.foo()': (u8, u32)
443..446 'opt': Opt<u8>
465..466 'f': fn(u8) -> u32
487..490 'opt': Opt<u8>
487..497 'opt.map(f)': Opt<u32>
495..496 'f': fn(u8) -> u32
"#]],
);
}
#[test]
fn fn_trait_deref_with_ty_default() {
check_infer(
r#"
#[lang = "deref"]
trait Deref {
type Target;
fn deref(&self) -> &Self::Target;
}
#[lang="fn_once"]
trait FnOnce<Args> {
type Output;
fn call_once(self, args: Args) -> Self::Output;
}
struct Foo;
impl Foo {
fn foo(&self) -> usize {}
}
struct Lazy<T, F = fn() -> T>(F);
impl<T, F> Lazy<T, F> {
pub fn new(f: F) -> Lazy<T, F> {}
}
impl<T, F: FnOnce() -> T> Deref for Lazy<T, F> {
type Target = T;
}
fn test() {
let lazy1: Lazy<Foo, _> = Lazy::new(|| Foo);
let r1 = lazy1.foo();
fn make_foo_fn() -> Foo {}
let make_foo_fn_ptr: fn() -> Foo = make_foo_fn;
let lazy2: Lazy<Foo, _> = Lazy::new(make_foo_fn_ptr);
let r2 = lazy2.foo();
}
"#,
expect![[r#"
64..68 'self': &Self
165..169 'self': Self
171..175 'args': Args
239..243 'self': &Foo
254..256 '{}': ()
334..335 'f': F
354..356 '{}': ()
443..689 '{ ...o(); }': ()
453..458 'lazy1': Lazy<Foo, || -> Foo>
475..484 'Lazy::new': fn new<Foo, || -> Foo>(|| -> Foo) -> Lazy<Foo, || -> Foo>
475..492 'Lazy::...| Foo)': Lazy<Foo, || -> Foo>
485..491 '|| Foo': || -> Foo
488..491 'Foo': Foo
502..504 'r1': usize
507..512 'lazy1': Lazy<Foo, || -> Foo>
507..518 'lazy1.foo()': usize
560..575 'make_foo_fn_ptr': fn() -> Foo
591..602 'make_foo_fn': fn make_foo_fn() -> Foo
612..617 'lazy2': Lazy<Foo, fn() -> Foo>
634..643 'Lazy::new': fn new<Foo, fn() -> Foo>(fn() -> Foo) -> Lazy<Foo, fn() -> Foo>
634..660 'Lazy::...n_ptr)': Lazy<Foo, fn() -> Foo>
644..659 'make_foo_fn_ptr': fn() -> Foo
670..672 'r2': usize
675..680 'lazy2': Lazy<Foo, fn() -> Foo>
675..686 'lazy2.foo()': usize
549..551 '{}': ()
"#]],
);
}
#[test]
fn closure_1() {
check_infer(
r#"
#[lang = "fn_once"]
trait FnOnce<Args> {
type Output;
}
enum Option<T> { Some(T), None }
impl<T> Option<T> {
fn map<U, F: FnOnce(T) -> U>(self, f: F) -> Option<U> {}
}
fn test() {
let x = Option::Some(1u32);
x.map(|v| v + 1);
x.map(|_v| 1u64);
let y: Option<i64> = x.map(|_v| 1);
}
"#,
expect![[r#"
147..151 'self': Option<T>
153..154 'f': F
172..174 '{}': ()
188..307 '{ ... 1); }': ()
198..199 'x': Option<u32>
202..214 'Option::Some': Some<u32>(u32) -> Option<u32>
202..220 'Option...(1u32)': Option<u32>
215..219 '1u32': u32
226..227 'x': Option<u32>
226..242 'x.map(...v + 1)': Option<u32>
232..241 '|v| v + 1': |u32| -> u32
233..234 'v': u32
236..237 'v': u32
236..241 'v + 1': u32
240..241 '1': u32
248..249 'x': Option<u32>
248..264 'x.map(... 1u64)': Option<u64>
254..263 '|_v| 1u64': |u32| -> u64
255..257 '_v': u32
259..263 '1u64': u64
274..275 'y': Option<i64>
291..292 'x': Option<u32>
291..304 'x.map(|_v| 1)': Option<i64>
297..303 '|_v| 1': |u32| -> i64
298..300 '_v': u32
302..303 '1': i64
"#]],
);
}
#[test]
fn closure_2() {
check_infer(
r#"
trait FnOnce<Args> {
type Output;
}
fn test<F: FnOnce(u32) -> u64>(f: F) {
f(1);
let g = |v| v + 1;
g(1u64);
let h = |v| 1u128 + v;
}
"#,
expect![[r#"
72..73 'f': F
78..154 '{ ...+ v; }': ()
84..85 'f': F
84..88 'f(1)': {unknown}
86..87 '1': i32
98..99 'g': |u64| -> i32
102..111 '|v| v + 1': |u64| -> i32
103..104 'v': u64
106..107 'v': u64
106..111 'v + 1': i32
110..111 '1': i32
117..118 'g': |u64| -> i32
117..124 'g(1u64)': i32
119..123 '1u64': u64
134..135 'h': |u128| -> u128
138..151 '|v| 1u128 + v': |u128| -> u128
139..140 'v': u128
142..147 '1u128': u128
142..151 '1u128 + v': u128
150..151 'v': u128
"#]],
);
}
#[test]
fn closure_as_argument_inference_order() {
check_infer(
r#"
#[lang = "fn_once"]
trait FnOnce<Args> {
type Output;
}
fn foo1<T, U, F: FnOnce(T) -> U>(x: T, f: F) -> U {}
fn foo2<T, U, F: FnOnce(T) -> U>(f: F, x: T) -> U {}
struct S;
impl S {
fn method(self) -> u64;
fn foo1<T, U, F: FnOnce(T) -> U>(self, x: T, f: F) -> U {}
fn foo2<T, U, F: FnOnce(T) -> U>(self, f: F, x: T) -> U {}
}
fn test() {
let x1 = foo1(S, |s| s.method());
let x2 = foo2(|s| s.method(), S);
let x3 = S.foo1(S, |s| s.method());
let x4 = S.foo2(|s| s.method(), S);
}
"#,
expect![[r#"
94..95 'x': T
100..101 'f': F
111..113 '{}': ()
147..148 'f': F
153..154 'x': T
164..166 '{}': ()
201..205 'self': S
253..257 'self': S
259..260 'x': T
265..266 'f': F
276..278 '{}': ()
316..320 'self': S
322..323 'f': F
328..329 'x': T
339..341 '{}': ()
355..514 '{ ... S); }': ()
365..367 'x1': u64
370..374 'foo1': fn foo1<S, u64, |S| -> u64>(S, |S| -> u64) -> u64
370..393 'foo1(S...hod())': u64
375..376 'S': S
378..392 '|s| s.method()': |S| -> u64
379..380 's': S
382..383 's': S
382..392 's.method()': u64
403..405 'x2': u64
408..412 'foo2': fn foo2<S, u64, |S| -> u64>(|S| -> u64, S) -> u64
408..431 'foo2(|...(), S)': u64
413..427 '|s| s.method()': |S| -> u64
414..415 's': S
417..418 's': S
417..427 's.method()': u64
429..430 'S': S
441..443 'x3': u64
446..447 'S': S
446..471 'S.foo1...hod())': u64
453..454 'S': S
456..470 '|s| s.method()': |S| -> u64
457..458 's': S
460..461 's': S
460..470 's.method()': u64
481..483 'x4': u64
486..487 'S': S
486..511 'S.foo2...(), S)': u64
493..507 '|s| s.method()': |S| -> u64
494..495 's': S
497..498 's': S
497..507 's.method()': u64
509..510 'S': S
"#]],
);
}
#[test]
fn fn_item_fn_trait() {
check_types(
r#"
#[lang = "fn_once"]
trait FnOnce<Args> {
type Output;
}
struct S;
fn foo() -> S {}
fn takes_closure<U, F: FnOnce() -> U>(f: F) -> U { f() }
fn test() {
takes_closure(foo);
} //^^^^^^^^^^^^^^^^^^ S
"#,
);
}
#[test]
fn unselected_projection_in_trait_env_1() {
check_types(
r#"
//- /main.rs
trait Trait {
type Item;
}
trait Trait2 {
fn foo(&self) -> u32;
}
fn test<T: Trait>() where T::Item: Trait2 {
let x: T::Item = no_matter;
x.foo();
} //^ u32
"#,
);
}
#[test]
fn unselected_projection_in_trait_env_2() {
check_types(
r#"
trait Trait<T> {
type Item;
}
trait Trait2 {
fn foo(&self) -> u32;
}
fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
let x: T::Item = no_matter;
x.foo();
} //^ u32
"#,
);
}
#[test]
fn unselected_projection_on_impl_self() {
check_infer(
r#"
//- /main.rs
trait Trait {
type Item;
fn f(&self, x: Self::Item);
}
struct S;
impl Trait for S {
type Item = u32;
fn f(&self, x: Self::Item) { let y = x; }
}
struct S2;
impl Trait for S2 {
type Item = i32;
fn f(&self, x: <Self>::Item) { let y = x; }
}
"#,
expect![[r#"
40..44 'self': &Self
46..47 'x': Trait::Item<Self>
126..130 'self': &S
132..133 'x': u32
147..161 '{ let y = x; }': ()
153..154 'y': u32
157..158 'x': u32
228..232 'self': &S2
234..235 'x': i32
251..265 '{ let y = x; }': ()
257..258 'y': i32
261..262 'x': i32
"#]],
);
}
#[test]
fn unselected_projection_on_trait_self() {
check_types(
r#"
trait Trait {
type Item;
fn f(&self) -> Self::Item { loop {} }
}
struct S;
impl Trait for S {
type Item = u32;
}
fn test() {
S.f();
} //^ u32
"#,
);
}
#[test]
fn unselected_projection_chalk_fold() {
check_types(
r#"
trait Interner {}
trait Fold<I: Interner, TI = I> {
type Result;
}
struct Ty<I: Interner> {}
impl<I: Interner, TI: Interner> Fold<I, TI> for Ty<I> {
type Result = Ty<TI>;
}
fn fold<I: Interner, T>(interner: &I, t: T) -> T::Result
where
T: Fold<I, I>,
{
loop {}
}
fn foo<I: Interner>(interner: &I, t: Ty<I>) {
fold(interner, t);
} //^ Ty<I>
"#,
);
}
#[test]
fn trait_impl_self_ty() {
check_types(
r#"
trait Trait<T> {
fn foo(&self);
}
struct S;
impl Trait<Self> for S {}
fn test() {
S.foo();
} //^ ()
"#,
);
}
#[test]
fn trait_impl_self_ty_cycle() {
check_types(
r#"
trait Trait {
fn foo(&self);
}
struct S<T>;
impl Trait for S<Self> {}
fn test() {
S.foo();
} //^ {unknown}
"#,
);
}
#[test]
fn unselected_projection_in_trait_env_cycle_1() {
// this is a legitimate cycle
check_types(
r#"
trait Trait {
type Item;
}
trait Trait2<T> {}
fn test<T: Trait>() where T: Trait2<T::Item> {
let x: T::Item = no_matter;
} //^ {unknown}
"#,
);
}
#[test]
fn unselected_projection_in_trait_env_cycle_2() {
// this is a legitimate cycle
check_types(
r#"
//- /main.rs
trait Trait<T> {
type Item;
}
fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
let x: T::Item = no_matter;
} //^ {unknown}
"#,
);
}
#[test]
fn inline_assoc_type_bounds_1() {
check_types(
r#"
trait Iterator {
type Item;
}
trait OtherTrait<T> {
fn foo(&self) -> T;
}
// workaround for Chalk assoc type normalization problems
pub struct S<T>;
impl<T: Iterator> Iterator for S<T> {
type Item = <T as Iterator>::Item;
}
fn test<I: Iterator<Item: OtherTrait<u32>>>() {
let x: <S<I> as Iterator>::Item;
x.foo();
} //^ u32
"#,
);
}
#[test]
fn inline_assoc_type_bounds_2() {
check_types(
r#"
trait Iterator {
type Item;
}
fn test<I: Iterator<Item: Iterator<Item = u32>>>() {
let x: <<I as Iterator>::Item as Iterator>::Item;
x;
} //^ u32
"#,
);
}
#[test]
fn proc_macro_server_types() {
check_infer(
r#"
macro_rules! with_api {
($S:ident, $self:ident, $m:ident) => {
$m! {
TokenStream {
fn new() -> $S::TokenStream;
},
Group {
},
}
};
}
macro_rules! associated_item {
(type TokenStream) =>
(type TokenStream: 'static;);
(type Group) =>
(type Group: 'static;);
($($item:tt)*) => ($($item)*;)
}
macro_rules! declare_server_traits {
($($name:ident {
$(fn $method:ident($($arg:ident: $arg_ty:ty),* $(,)?) $(-> $ret_ty:ty)?;)*
}),* $(,)?) => {
pub trait Types {
$(associated_item!(type $name);)*
}
$(pub trait $name: Types {
$(associated_item!(fn $method($($arg: $arg_ty),*) $(-> $ret_ty)?);)*
})*
pub trait Server: Types $(+ $name)* {}
impl<S: Types $(+ $name)*> Server for S {}
}
}
with_api!(Self, self_, declare_server_traits);
struct G {}
struct T {}
struct Rustc;
impl Types for Rustc {
type TokenStream = T;
type Group = G;
}
fn make<T>() -> T { loop {} }
impl TokenStream for Rustc {
fn new() -> Self::TokenStream {
let group: Self::Group = make();
make()
}
}
"#,
expect![[r#"
1061..1072 '{ loop {} }': T
1063..1070 'loop {}': !
1068..1070 '{}': ()
1136..1199 '{ ... }': T
1150..1155 'group': G
1171..1175 'make': fn make<G>() -> G
1171..1177 'make()': G
1187..1191 'make': fn make<T>() -> T
1187..1193 'make()': T
"#]],
);
}
#[test]
fn unify_impl_trait() {
check_infer_with_mismatches(
r#"
trait Trait<T> {}
fn foo(x: impl Trait<u32>) { loop {} }
fn bar<T>(x: impl Trait<T>) -> T { loop {} }
struct S<T>(T);
impl<T> Trait<T> for S<T> {}
fn default<T>() -> T { loop {} }
fn test() -> impl Trait<i32> {
let s1 = S(default());
foo(s1);
let x: i32 = bar(S(default()));
S(default())
}
"#,
expect![[r#"
26..27 'x': impl Trait<u32>
46..57 '{ loop {} }': ()
48..55 'loop {}': !
53..55 '{}': ()
68..69 'x': impl Trait<T>
91..102 '{ loop {} }': T
93..100 'loop {}': !
98..100 '{}': ()
171..182 '{ loop {} }': T
173..180 'loop {}': !
178..180 '{}': ()
213..309 '{ ...t()) }': S<{unknown}>
223..225 's1': S<u32>
228..229 'S': S<u32>(u32) -> S<u32>
228..240 'S(default())': S<u32>
230..237 'default': fn default<u32>() -> u32
230..239 'default()': u32
246..249 'foo': fn foo(S<u32>)
246..253 'foo(s1)': ()
250..252 's1': S<u32>
263..264 'x': i32
272..275 'bar': fn bar<i32>(S<i32>) -> i32
272..289 'bar(S(...lt()))': i32
276..277 'S': S<i32>(i32) -> S<i32>
276..288 'S(default())': S<i32>
278..285 'default': fn default<i32>() -> i32
278..287 'default()': i32
295..296 'S': S<{unknown}>({unknown}) -> S<{unknown}>
295..307 'S(default())': S<{unknown}>
297..304 'default': fn default<{unknown}>() -> {unknown}
297..306 'default()': {unknown}
"#]],
);
}
#[test]
fn assoc_types_from_bounds() {
check_infer(
r#"
//- /main.rs
#[lang = "fn_once"]
trait FnOnce<Args> {
type Output;
}
trait T {
type O;
}
impl T for () {
type O = ();
}
fn f<X, F>(_v: F)
where
X: T,
F: FnOnce(&X::O),
{ }
fn main() {
f::<(), _>(|z| { z; });
}
"#,
expect![[r#"
133..135 '_v': F
178..181 '{ }': ()
193..224 '{ ... }); }': ()
199..209 'f::<(), _>': fn f<(), |&()| -> ()>(|&()| -> ())
199..221 'f::<()... z; })': ()
210..220 '|z| { z; }': |&()| -> ()
211..212 'z': &()
214..220 '{ z; }': ()
216..217 'z': &()
"#]],
);
}
#[test]
fn associated_type_bound() {
check_types(
r#"
pub trait Trait {
type Item: OtherTrait<u32>;
}
pub trait OtherTrait<T> {
fn foo(&self) -> T;
}
// this is just a workaround for chalk#234
pub struct S<T>;
impl<T: Trait> Trait for S<T> {
type Item = <T as Trait>::Item;
}
fn test<T: Trait>() {
let y: <S<T> as Trait>::Item = no_matter;
y.foo();
} //^ u32
"#,
);
}
#[test]
fn dyn_trait_through_chalk() {
check_types(
r#"
struct Box<T> {}
#[lang = "deref"]
trait Deref {
type Target;
}
impl<T> Deref for Box<T> {
type Target = T;
}
trait Trait {
fn foo(&self);
}
fn test(x: Box<dyn Trait>) {
x.foo();
} //^ ()
"#,
);
}
#[test]
fn string_to_owned() {
check_types(
r#"
struct String {}
pub trait ToOwned {
type Owned;
fn to_owned(&self) -> Self::Owned;
}
impl ToOwned for str {
type Owned = String;
}
fn test() {
"foo".to_owned();
} //^ String
"#,
);
}
#[test]
fn iterator_chain() {
check_infer(
r#"
//- /main.rs
#[lang = "fn_once"]
trait FnOnce<Args> {
type Output;
}
#[lang = "fn_mut"]
trait FnMut<Args>: FnOnce<Args> { }
enum Option<T> { Some(T), None }
use Option::*;
pub trait Iterator {
type Item;
fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>
where
F: FnMut(Self::Item) -> Option<B>,
{ loop {} }
fn for_each<F>(self, f: F)
where
F: FnMut(Self::Item),
{ loop {} }
}
pub trait IntoIterator {
type Item;
type IntoIter: Iterator<Item = Self::Item>;
fn into_iter(self) -> Self::IntoIter;
}
pub struct FilterMap<I, F> { }
impl<B, I: Iterator, F> Iterator for FilterMap<I, F>
where
F: FnMut(I::Item) -> Option<B>,
{
type Item = B;
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<I: Iterator> IntoIterator for I {
type Item = I::Item;
type IntoIter = I;
fn into_iter(self) -> I {
self
}
}
struct Vec<T> {}
impl<T> Vec<T> {
fn new() -> Self { loop {} }
}
impl<T> IntoIterator for Vec<T> {
type Item = T;
type IntoIter = IntoIter<T>;
}
pub struct IntoIter<T> { }
impl<T> Iterator for IntoIter<T> {
type Item = T;
}
fn main() {
Vec::<i32>::new().into_iter()
.filter_map(|x| if x > 0 { Some(x as u32) } else { None })
.for_each(|y| { y; });
}
"#,
expect![[r#"
226..230 'self': Self
232..233 'f': F
317..328 '{ loop {} }': FilterMap<Self, F>
319..326 'loop {}': !
324..326 '{}': ()
349..353 'self': Self
355..356 'f': F
405..416 '{ loop {} }': ()
407..414 'loop {}': !
412..414 '{}': ()
525..529 'self': Self
854..858 'self': I
865..885 '{ ... }': I
875..879 'self': I
944..955 '{ loop {} }': Vec<T>
946..953 'loop {}': !
951..953 '{}': ()
1142..1269 '{ ... }); }': ()
1148..1163 'Vec::<i32>::new': fn new<i32>() -> Vec<i32>
1148..1165 'Vec::<...:new()': Vec<i32>
1148..1177 'Vec::<...iter()': IntoIter<i32>
1148..1240 'Vec::<...one })': FilterMap<IntoIter<i32>, |i32| -> Option<u32>>
1148..1266 'Vec::<... y; })': ()
1194..1239 '|x| if...None }': |i32| -> Option<u32>
1195..1196 'x': i32
1198..1239 'if x >...None }': Option<u32>
1201..1202 'x': i32
1201..1206 'x > 0': bool
1205..1206 '0': i32
1207..1225 '{ Some...u32) }': Option<u32>
1209..1213 'Some': Some<u32>(u32) -> Option<u32>
1209..1223 'Some(x as u32)': Option<u32>
1214..1215 'x': i32
1214..1222 'x as u32': u32
1231..1239 '{ None }': Option<u32>
1233..1237 'None': Option<u32>
1255..1265 '|y| { y; }': |u32| -> ()
1256..1257 'y': u32
1259..1265 '{ y; }': ()
1261..1262 'y': u32
"#]],
);
}
#[test]
fn nested_assoc() {
check_types(
r#"
struct Bar;
struct Foo;
trait A {
type OutputA;
}
impl A for Bar {
type OutputA = Foo;
}
trait B {
type Output;
fn foo() -> Self::Output;
}
impl<T:A> B for T {
type Output = T::OutputA;
fn foo() -> Self::Output { loop {} }
}
fn main() {
Bar::foo();
} //^ Foo
"#,
);
}
#[test]
fn trait_object_no_coercion() {
check_infer_with_mismatches(
r#"
trait Foo {}
fn foo(x: &dyn Foo) {}
fn test(x: &dyn Foo) {
foo(x);
}
"#,
expect![[r#"
21..22 'x': &dyn Foo
34..36 '{}': ()
46..47 'x': &dyn Foo
59..74 '{ foo(x); }': ()
65..68 'foo': fn foo(&dyn Foo)
65..71 'foo(x)': ()
69..70 'x': &dyn Foo
"#]],
);
}
#[test]
fn builtin_copy() {
check_infer_with_mismatches(
r#"
#[lang = "copy"]
trait Copy {}
struct IsCopy;
impl Copy for IsCopy {}
struct NotCopy;
trait Test { fn test(&self) -> bool; }
impl<T: Copy> Test for T {}
fn test() {
IsCopy.test();
NotCopy.test();
(IsCopy, IsCopy).test();
(IsCopy, NotCopy).test();
}
"#,
expect![[r#"
110..114 'self': &Self
166..267 '{ ...t(); }': ()
172..178 'IsCopy': IsCopy
172..185 'IsCopy.test()': bool
191..198 'NotCopy': NotCopy
191..205 'NotCopy.test()': {unknown}
211..227 '(IsCop...sCopy)': (IsCopy, IsCopy)
211..234 '(IsCop...test()': bool
212..218 'IsCopy': IsCopy
220..226 'IsCopy': IsCopy
240..257 '(IsCop...tCopy)': (IsCopy, NotCopy)
240..264 '(IsCop...test()': {unknown}
241..247 'IsCopy': IsCopy
249..256 'NotCopy': NotCopy
"#]],
);
}
#[test]
fn builtin_fn_def_copy() {
check_infer_with_mismatches(
r#"
#[lang = "copy"]
trait Copy {}
fn foo() {}
fn bar<T: Copy>(T) -> T {}
struct Struct(usize);
enum Enum { Variant(usize) }
trait Test { fn test(&self) -> bool; }
impl<T: Copy> Test for T {}
fn test() {
foo.test();
bar.test();
Struct.test();
Enum::Variant.test();
}
"#,
expect![[r#"
41..43 '{}': ()
60..61 'T': {unknown}
68..70 '{}': ()
68..70: expected T, got ()
145..149 'self': &Self
201..281 '{ ...t(); }': ()
207..210 'foo': fn foo()
207..217 'foo.test()': bool
223..226 'bar': fn bar<{unknown}>({unknown}) -> {unknown}
223..233 'bar.test()': bool
239..245 'Struct': Struct(usize) -> Struct
239..252 'Struct.test()': bool
258..271 'Enum::Variant': Variant(usize) -> Enum
258..278 'Enum::...test()': bool
"#]],
);
}
#[test]
fn builtin_fn_ptr_copy() {
check_infer_with_mismatches(
r#"
#[lang = "copy"]
trait Copy {}
trait Test { fn test(&self) -> bool; }
impl<T: Copy> Test for T {}
fn test(f1: fn(), f2: fn(usize) -> u8, f3: fn(u8, u8) -> &u8) {
f1.test();
f2.test();
f3.test();
}
"#,
expect![[r#"
54..58 'self': &Self
108..110 'f1': fn()
118..120 'f2': fn(usize) -> u8
139..141 'f3': fn(u8, u8) -> &u8
162..210 '{ ...t(); }': ()
168..170 'f1': fn()
168..177 'f1.test()': bool
183..185 'f2': fn(usize) -> u8
183..192 'f2.test()': bool
198..200 'f3': fn(u8, u8) -> &u8
198..207 'f3.test()': bool
"#]],
);
}
#[test]
fn builtin_sized() {
check_infer_with_mismatches(
r#"
#[lang = "sized"]
trait Sized {}
trait Test { fn test(&self) -> bool; }
impl<T: Sized> Test for T {}
fn test() {
1u8.test();
(*"foo").test(); // not Sized
(1u8, 1u8).test();
(1u8, *"foo").test(); // not Sized
}
"#,
expect![[r#"
56..60 'self': &Self
113..228 '{ ...ized }': ()
119..122 '1u8': u8
119..129 '1u8.test()': bool
135..150 '(*"foo").test()': {unknown}
136..142 '*"foo"': str
137..142 '"foo"': &str
169..179 '(1u8, 1u8)': (u8, u8)
169..186 '(1u8, ...test()': bool
170..173 '1u8': u8
175..178 '1u8': u8
192..205 '(1u8, *"foo")': (u8, str)
192..212 '(1u8, ...test()': {unknown}
193..196 '1u8': u8
198..204 '*"foo"': str
199..204 '"foo"': &str
"#]],
);
}
#[test]
fn integer_range_iterate() {
check_types(
r#"
//- /main.rs crate:main deps:core
fn test() {
for x in 0..100 { x; }
} //^ i32
//- /core.rs crate:core
pub mod ops {
pub struct Range<Idx> {
pub start: Idx,
pub end: Idx,
}
}
pub mod iter {
pub trait Iterator {
type Item;
}
pub trait IntoIterator {
type Item;
type IntoIter: Iterator<Item = Self::Item>;
}
impl<T> IntoIterator for T where T: Iterator {
type Item = <T as Iterator>::Item;
type IntoIter = Self;
}
}
trait Step {}
impl Step for i32 {}
impl Step for i64 {}
impl<A: Step> iter::Iterator for ops::Range<A> {
type Item = A;
}
"#,
);
}
#[test]
fn infer_closure_arg() {
check_infer(
r#"
//- /lib.rs
enum Option<T> {
None,
Some(T)
}
fn foo() {
let s = Option::None;
let f = |x: Option<i32>| {};
(&f)(s)
}
"#,
expect![[r#"
52..126 '{ ...)(s) }': ()
62..63 's': Option<i32>
66..78 'Option::None': Option<i32>
88..89 'f': |Option<i32>| -> ()
92..111 '|x: Op...2>| {}': |Option<i32>| -> ()
93..94 'x': Option<i32>
109..111 '{}': ()
117..124 '(&f)(s)': ()
118..120 '&f': &|Option<i32>| -> ()
119..120 'f': |Option<i32>| -> ()
122..123 's': Option<i32>
"#]],
);
}
#[test]
fn infer_fn_trait_arg() {
check_infer(
r#"
//- /lib.rs deps:std
#[lang = "fn_once"]
pub trait FnOnce<Args> {
type Output;
extern "rust-call" fn call_once(&self, args: Args) -> Self::Output;
}
#[lang = "fn"]
pub trait Fn<Args>:FnOnce<Args> {
extern "rust-call" fn call(&self, args: Args) -> Self::Output;
}
enum Option<T> {
None,
Some(T)
}
fn foo<F, T>(f: F) -> T
where
F: Fn(Option<i32>) -> T,
{
let s = None;
f(s)
}
"#,
expect![[r#"
101..105 'self': &Self
107..111 'args': Args
220..224 'self': &Self
226..230 'args': Args
313..314 'f': F
359..389 '{ ...f(s) }': T
369..370 's': Option<i32>
373..377 'None': Option<i32>
383..384 'f': F
383..387 'f(s)': T
385..386 's': Option<i32>
"#]],
);
}
#[test]
fn infer_box_fn_arg() {
check_infer(
r#"
//- /lib.rs deps:std
#[lang = "fn_once"]
pub trait FnOnce<Args> {
type Output;
extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
}
#[lang = "deref"]
pub trait Deref {
type Target: ?Sized;
fn deref(&self) -> &Self::Target;
}
#[lang = "owned_box"]
pub struct Box<T: ?Sized> {
inner: *mut T,
}
impl<T: ?Sized> Deref for Box<T> {
type Target = T;
fn deref(&self) -> &T {
&self.inner
}
}
enum Option<T> {
None,
Some(T)
}
fn foo() {
let s = Option::None;
let f: Box<dyn FnOnce(&Option<i32>)> = box (|ps| {});
f(&s)
}
"#,
expect![[r#"
100..104 'self': Self
106..110 'args': Args
214..218 'self': &Self
384..388 'self': &Box<T>
396..423 '{ ... }': &T
406..417 '&self.inner': &*mut T
407..411 'self': &Box<T>
407..417 'self.inner': *mut T
478..575 '{ ...(&s) }': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
488..489 's': Option<i32>
492..504 'Option::None': Option<i32>
514..515 'f': Box<dyn FnOnce<(&Option<i32>,)>>
549..562 'box (|ps| {})': Box<|{unknown}| -> ()>
554..561 '|ps| {}': |{unknown}| -> ()
555..557 'ps': {unknown}
559..561 '{}': ()
568..569 'f': Box<dyn FnOnce<(&Option<i32>,)>>
568..573 'f(&s)': FnOnce::Output<dyn FnOnce<(&Option<i32>,)>, (&Option<i32>,)>
570..572 '&s': &Option<i32>
571..572 's': Option<i32>
"#]],
);
}
#[test]
fn infer_dyn_fn_output() {
check_types(
r#"
#[lang = "fn_once"]
pub trait FnOnce<Args> {
type Output;
extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
}
#[lang = "fn"]
pub trait Fn<Args>: FnOnce<Args> {
extern "rust-call" fn call(&self, args: Args) -> Self::Output;
}
fn foo() {
let f: &dyn Fn() -> i32;
f();
//^^^ i32
}"#,
);
}
#[test]
fn infer_dyn_fn_once_output() {
check_types(
r#"
#[lang = "fn_once"]
pub trait FnOnce<Args> {
type Output;
extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
}
fn foo() {
let f: dyn FnOnce() -> i32;
f();
//^^^ i32
}"#,
);
}
#[test]
fn variable_kinds_1() {
check_types(
r#"
trait Trait<T> { fn get(self, t: T) -> T; }
struct S;
impl Trait<u128> for S {}
impl Trait<f32> for S {}
fn test() {
S.get(1);
//^^^^^^^^ u128
S.get(1.);
//^^^^^^^^ f32
}
"#,
);
}
#[test]
fn variable_kinds_2() {
check_types(
r#"
trait Trait { fn get(self) -> Self; }
impl Trait for u128 {}
impl Trait for f32 {}
fn test() {
1.get();
//^^^^^^^ u128
(1.).get();
//^^^^^^^^^^ f32
}
"#,
);
}
#[test]
fn underscore_import() {
check_types(
r#"
mod tr {
pub trait Tr {
fn method(&self) -> u8 { 0 }
}
}
struct Tr;
impl crate::tr::Tr for Tr {}
use crate::tr::Tr as _;
fn test() {
Tr.method();
//^^^^^^^^^^^ u8
}
"#,
);
}