diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:11:38 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:13:23 +0000 |
commit | 20431706a863f92cb37dc512fef6e48d192aaf2c (patch) | |
tree | 2867f13f5fd5437ba628c67d7f87309ccadcd286 /src/test/ui/borrowck | |
parent | Releasing progress-linux version 1.65.0+dfsg1-2~progress7.99u1. (diff) | |
download | rustc-20431706a863f92cb37dc512fef6e48d192aaf2c.tar.xz rustc-20431706a863f92cb37dc512fef6e48d192aaf2c.zip |
Merging upstream version 1.66.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
44 files changed, 632 insertions, 65 deletions
diff --git a/src/test/ui/borrowck/anonymous-region-in-apit.rs b/src/test/ui/borrowck/anonymous-region-in-apit.rs new file mode 100644 index 000000000..7799a7cb1 --- /dev/null +++ b/src/test/ui/borrowck/anonymous-region-in-apit.rs @@ -0,0 +1,12 @@ +#![feature(anonymous_lifetime_in_impl_trait)] + +trait Foo<T> { + fn bar(self, baz: T); +} + +fn qux(foo: impl Foo<&str>) { + |baz: &str| foo.bar(baz); + //~^ ERROR borrowed data escapes outside of closure +} + +fn main() {} diff --git a/src/test/ui/borrowck/anonymous-region-in-apit.stderr b/src/test/ui/borrowck/anonymous-region-in-apit.stderr new file mode 100644 index 000000000..9e100f8ac --- /dev/null +++ b/src/test/ui/borrowck/anonymous-region-in-apit.stderr @@ -0,0 +1,16 @@ +error[E0521]: borrowed data escapes outside of closure + --> $DIR/anonymous-region-in-apit.rs:8:17 + | +LL | fn qux(foo: impl Foo<&str>) { + | --- lifetime `'2` appears in the type of `foo` +LL | |baz: &str| foo.bar(baz); + | --- - ^^^^^^^^^^^^ + | | | | + | | | `baz` escapes the closure body here + | | | argument requires that `'1` must outlive `'2` + | | let's call the lifetime of this reference `'1` + | `baz` is a reference that is only valid in the closure body + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0521`. diff --git a/src/test/ui/borrowck/borrowck-block-unint.stderr b/src/test/ui/borrowck/borrowck-block-unint.stderr index e720db1c6..f47921a97 100644 --- a/src/test/ui/borrowck/borrowck-block-unint.stderr +++ b/src/test/ui/borrowck/borrowck-block-unint.stderr @@ -7,6 +7,11 @@ LL | force(|| { | ^^ `x` used here but it isn't initialized LL | println!("{}", x); | - borrow occurs due to use in closure + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-break-uninit-2.stderr b/src/test/ui/borrowck/borrowck-break-uninit-2.stderr index 91038b3ad..ea93a8f40 100644 --- a/src/test/ui/borrowck/borrowck-break-uninit-2.stderr +++ b/src/test/ui/borrowck/borrowck-break-uninit-2.stderr @@ -8,6 +8,10 @@ LL | println!("{}", x); | ^ `x` used here but it isn't initialized | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-break-uninit.stderr b/src/test/ui/borrowck/borrowck-break-uninit.stderr index 8d0c9582f..a7a8fc2ff 100644 --- a/src/test/ui/borrowck/borrowck-break-uninit.stderr +++ b/src/test/ui/borrowck/borrowck-break-uninit.stderr @@ -8,6 +8,10 @@ LL | println!("{}", x); | ^ `x` used here but it isn't initialized | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-init-in-called-fn-expr.stderr b/src/test/ui/borrowck/borrowck-init-in-called-fn-expr.stderr index e8a2fbc91..1a22b5f09 100644 --- a/src/test/ui/borrowck/borrowck-init-in-called-fn-expr.stderr +++ b/src/test/ui/borrowck/borrowck-init-in-called-fn-expr.stderr @@ -5,6 +5,11 @@ LL | let i: isize; | - binding declared here but left uninitialized LL | i | ^ `i` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let i: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-init-in-fn-expr.stderr b/src/test/ui/borrowck/borrowck-init-in-fn-expr.stderr index 1e950d6a2..f1b9b9aa7 100644 --- a/src/test/ui/borrowck/borrowck-init-in-fn-expr.stderr +++ b/src/test/ui/borrowck/borrowck-init-in-fn-expr.stderr @@ -5,6 +5,11 @@ LL | let i: isize; | - binding declared here but left uninitialized LL | i | ^ `i` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let i: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-init-in-fru.stderr b/src/test/ui/borrowck/borrowck-init-in-fru.stderr index 83a3e3e0e..39b28811a 100644 --- a/src/test/ui/borrowck/borrowck-init-in-fru.stderr +++ b/src/test/ui/borrowck/borrowck-init-in-fru.stderr @@ -5,6 +5,11 @@ LL | let mut origin: Point; | ---------- binding declared here but left uninitialized LL | origin = Point { x: 10, ..origin }; | ^^^^^^^^^^^^^^^^^^^^^^^^^ `origin.y` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let mut origin: Point = todo!(); + | +++++++++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-init-op-equal.stderr b/src/test/ui/borrowck/borrowck-init-op-equal.stderr index 74704b2ab..ef0fa6df4 100644 --- a/src/test/ui/borrowck/borrowck-init-op-equal.stderr +++ b/src/test/ui/borrowck/borrowck-init-op-equal.stderr @@ -5,6 +5,11 @@ LL | let v: isize; | - binding declared here but left uninitialized LL | v += 1; | ^^^^^^ `v` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let v: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-init-plus-equal.stderr b/src/test/ui/borrowck/borrowck-init-plus-equal.stderr index 7542576d6..cec053318 100644 --- a/src/test/ui/borrowck/borrowck-init-plus-equal.stderr +++ b/src/test/ui/borrowck/borrowck-init-plus-equal.stderr @@ -5,6 +5,11 @@ LL | let mut v: isize; | ----- binding declared here but left uninitialized LL | v = v + 1; | ^ `v` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let mut v: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-mut-borrow-linear-errors.stderr b/src/test/ui/borrowck/borrowck-mut-borrow-linear-errors.stderr index 15ac73760..d2b845619 100644 --- a/src/test/ui/borrowck/borrowck-mut-borrow-linear-errors.stderr +++ b/src/test/ui/borrowck/borrowck-mut-borrow-linear-errors.stderr @@ -25,7 +25,10 @@ error[E0499]: cannot borrow `x` as mutable more than once at a time --> $DIR/borrowck-mut-borrow-linear-errors.rs:12:30 | LL | _ => { addr.push(&mut x); } - | ^^^^^^ `x` was mutably borrowed here in the previous iteration of the loop + | ----------^^^^^^- + | | | + | | `x` was mutably borrowed here in the previous iteration of the loop + | first borrow used here, in later iteration of loop error: aborting due to 3 previous errors diff --git a/src/test/ui/borrowck/borrowck-return.stderr b/src/test/ui/borrowck/borrowck-return.stderr index 1c916e223..9799357c9 100644 --- a/src/test/ui/borrowck/borrowck-return.stderr +++ b/src/test/ui/borrowck/borrowck-return.stderr @@ -5,6 +5,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | return x; | ^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-storage-dead.stderr b/src/test/ui/borrowck/borrowck-storage-dead.stderr index 2cea4392d..3a413153a 100644 --- a/src/test/ui/borrowck/borrowck-storage-dead.stderr +++ b/src/test/ui/borrowck/borrowck-storage-dead.stderr @@ -5,6 +5,11 @@ LL | let x: i32; | - binding declared here but left uninitialized LL | let _ = x + 1; | ^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: i32 = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-uninit-after-item.stderr b/src/test/ui/borrowck/borrowck-uninit-after-item.stderr index 588b1b0c9..071598b42 100644 --- a/src/test/ui/borrowck/borrowck-uninit-after-item.stderr +++ b/src/test/ui/borrowck/borrowck-uninit-after-item.stderr @@ -6,6 +6,11 @@ LL | let bar; LL | fn baz(_x: isize) { } LL | baz(bar); | ^^^ `bar` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let bar = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-uninit-field-access.stderr b/src/test/ui/borrowck/borrowck-uninit-field-access.stderr index 6a38a7989..f0f4ad704 100644 --- a/src/test/ui/borrowck/borrowck-uninit-field-access.stderr +++ b/src/test/ui/borrowck/borrowck-uninit-field-access.stderr @@ -5,6 +5,11 @@ LL | let mut a: Point; | ----- binding declared here but left uninitialized LL | let _ = a.x + 1; | ^^^ `a.x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let mut a: Point = Default::default(); + | ++++++++++++++++++++ error[E0382]: use of moved value: `line1.origin` --> $DIR/borrowck-uninit-field-access.rs:25:13 diff --git a/src/test/ui/borrowck/borrowck-uninit-in-assignop.stderr b/src/test/ui/borrowck/borrowck-uninit-in-assignop.stderr index 744cb14e6..fdbb451bd 100644 --- a/src/test/ui/borrowck/borrowck-uninit-in-assignop.stderr +++ b/src/test/ui/borrowck/borrowck-uninit-in-assignop.stderr @@ -5,6 +5,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x += 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:9:5 @@ -13,6 +18,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x -= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:12:5 @@ -21,6 +31,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x *= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:15:5 @@ -29,6 +44,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x /= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:18:5 @@ -37,6 +57,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x %= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:21:5 @@ -45,6 +70,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x ^= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:24:5 @@ -53,6 +83,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x &= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:27:5 @@ -61,6 +96,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x |= 1; | ^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:30:5 @@ -69,6 +109,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x <<= 1; | ^^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-in-assignop.rs:33:5 @@ -77,6 +122,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | x >>= 1; | ^^^^^^^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to 10 previous errors diff --git a/src/test/ui/borrowck/borrowck-uninit-ref-chain.stderr b/src/test/ui/borrowck/borrowck-uninit-ref-chain.stderr index c486cb6dd..73fded754 100644 --- a/src/test/ui/borrowck/borrowck-uninit-ref-chain.stderr +++ b/src/test/ui/borrowck/borrowck-uninit-ref-chain.stderr @@ -5,6 +5,11 @@ LL | let x: &&Box<i32>; | - binding declared here but left uninitialized LL | let _y = &**x; | ^^^^ `**x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: &&Box<i32> = todo!(); + | +++++++++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-ref-chain.rs:11:14 @@ -13,6 +18,11 @@ LL | let x: &&S<i32, i32>; | - binding declared here but left uninitialized LL | let _y = &**x; | ^^^^ `**x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: &&S<i32, i32> = todo!(); + | +++++++++ error[E0381]: used binding `x` isn't initialized --> $DIR/borrowck-uninit-ref-chain.rs:14:14 @@ -21,6 +31,11 @@ LL | let x: &&i32; | - binding declared here but left uninitialized LL | let _y = &**x; | ^^^^ `**x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: &&i32 = todo!(); + | +++++++++ error[E0381]: partially assigned binding `a` isn't fully initialized --> $DIR/borrowck-uninit-ref-chain.rs:18:5 diff --git a/src/test/ui/borrowck/borrowck-uninit.stderr b/src/test/ui/borrowck/borrowck-uninit.stderr index d5566691a..eeafc4ce1 100644 --- a/src/test/ui/borrowck/borrowck-uninit.stderr +++ b/src/test/ui/borrowck/borrowck-uninit.stderr @@ -5,6 +5,11 @@ LL | let x: isize; | - binding declared here but left uninitialized LL | foo(x); | ^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: isize = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-use-in-index-lvalue.stderr b/src/test/ui/borrowck/borrowck-use-in-index-lvalue.stderr index 459cf1398..18e808f10 100644 --- a/src/test/ui/borrowck/borrowck-use-in-index-lvalue.stderr +++ b/src/test/ui/borrowck/borrowck-use-in-index-lvalue.stderr @@ -5,6 +5,11 @@ LL | let w: &mut [isize]; | - binding declared here but left uninitialized LL | w[5] = 0; | ^^^^ `*w` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let w: &mut [isize] = todo!(); + | +++++++++ error[E0381]: used binding `w` isn't initialized --> $DIR/borrowck-use-in-index-lvalue.rs:6:5 @@ -13,6 +18,11 @@ LL | let mut w: &mut [isize]; | ----- binding declared here but left uninitialized LL | w[5] = 0; | ^^^^ `*w` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let mut w: &mut [isize] = todo!(); + | +++++++++ error: aborting due to 2 previous errors diff --git a/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast-trait.stderr b/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast-trait.stderr index 942ed4fc6..55f3ff553 100644 --- a/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast-trait.stderr +++ b/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast-trait.stderr @@ -5,6 +5,11 @@ LL | let x: &i32; | - binding declared here but left uninitialized LL | let y = x as *const dyn Foo; | ^ `*x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: &i32 = todo!(); + | +++++++++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast.stderr b/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast.stderr index f3289e239..ea3d0d3ef 100644 --- a/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast.stderr +++ b/src/test/ui/borrowck/borrowck-use-uninitialized-in-cast.stderr @@ -5,6 +5,11 @@ LL | let x: &i32; | - binding declared here but left uninitialized LL | let y = x as *const i32; | ^ `*x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: &i32 = todo!(); + | +++++++++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/borrowck-while-cond.stderr b/src/test/ui/borrowck/borrowck-while-cond.stderr index e41c1c55e..5d0194989 100644 --- a/src/test/ui/borrowck/borrowck-while-cond.stderr +++ b/src/test/ui/borrowck/borrowck-while-cond.stderr @@ -5,6 +5,11 @@ LL | let x: bool; | - binding declared here but left uninitialized LL | while x { } | ^ `x` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let x: bool = false; + | +++++++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/issue-102209.rs b/src/test/ui/borrowck/issue-102209.rs new file mode 100644 index 000000000..37628bff7 --- /dev/null +++ b/src/test/ui/borrowck/issue-102209.rs @@ -0,0 +1,28 @@ +use std::marker::PhantomData; + +pub struct NfaBuilder<'brand> { + brand: PhantomData<&'brand mut &'brand mut ()>, +} + +impl NfaBuilder<'_> { + pub fn with<R, F: FnOnce(NfaBuilder<'_>) -> R>(f: F) -> R { + Brand::with(|brand| { + f(Self { brand: brand.lt }) + //~^ ERROR lifetime may not live long enough + //~| ERROR lifetime may not live long enough + }) + } +} + +#[derive(Clone, Copy)] +pub struct Brand<'brand> { + lt: PhantomData<&'brand mut &'brand mut ()>, +} + +impl Brand<'_> { + pub fn with<R, F: FnOnce(Brand<'_>) -> R>(f: F) -> R { + f(Self { lt: PhantomData }) + } +} + +fn main() {} diff --git a/src/test/ui/borrowck/issue-102209.stderr b/src/test/ui/borrowck/issue-102209.stderr new file mode 100644 index 000000000..351de8217 --- /dev/null +++ b/src/test/ui/borrowck/issue-102209.stderr @@ -0,0 +1,22 @@ +error: lifetime may not live long enough + --> $DIR/issue-102209.rs:10:29 + | +LL | impl NfaBuilder<'_> { + | -- lifetime `'2` appears in the `impl`'s self type +LL | pub fn with<R, F: FnOnce(NfaBuilder<'_>) -> R>(f: F) -> R { +LL | Brand::with(|brand| { + | ----- has type `Brand<'1>` +LL | f(Self { brand: brand.lt }) + | ^^^^^^^^ this usage requires that `'1` must outlive `'2` + +error: lifetime may not live long enough + --> $DIR/issue-102209.rs:10:29 + | +LL | impl NfaBuilder<'_> { + | -- lifetime `'1` appears in the `impl`'s self type +... +LL | f(Self { brand: brand.lt }) + | ^^^^^^^^ this usage requires that `'1` must outlive `'static` + +error: aborting due to 2 previous errors + diff --git a/src/test/ui/borrowck/issue-103250.rs b/src/test/ui/borrowck/issue-103250.rs new file mode 100644 index 000000000..46565f61c --- /dev/null +++ b/src/test/ui/borrowck/issue-103250.rs @@ -0,0 +1,37 @@ +// edition:2021 + +type TranslateFn = Box<dyn Fn(String, String) -> String>; + +pub struct DeviceCluster { + devices: Vec<Device>, +} + +impl DeviceCluster { + pub async fn do_something(&mut self) -> Result<String, Box<dyn std::error::Error>> { + let mut last_error: Box<dyn std::error::Error>; + + for device in &mut self.devices { + match device.do_something().await { + Ok(info) => { + return Ok(info); + } + Err(e) => {} + } + } + + Err(last_error) + //~^ ERROR used binding `last_error` isn't initialized + } +} + +pub struct Device { + translate_fn: Option<TranslateFn>, +} + +impl Device { + pub async fn do_something(&mut self) -> Result<String, Box<dyn std::error::Error>> { + Ok(String::from("")) + } +} + +fn main() {} diff --git a/src/test/ui/borrowck/issue-103250.stderr b/src/test/ui/borrowck/issue-103250.stderr new file mode 100644 index 000000000..4a2378352 --- /dev/null +++ b/src/test/ui/borrowck/issue-103250.stderr @@ -0,0 +1,17 @@ +error[E0381]: used binding `last_error` isn't initialized + --> $DIR/issue-103250.rs:22:13 + | +LL | let mut last_error: Box<dyn std::error::Error>; + | -------------- binding declared here but left uninitialized +... +LL | Err(last_error) + | ^^^^^^^^^^ `last_error` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let mut last_error: Box<dyn std::error::Error> = todo!(); + | +++++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0381`. diff --git a/src/test/ui/borrowck/issue-103624.rs b/src/test/ui/borrowck/issue-103624.rs new file mode 100644 index 000000000..f1fa95f92 --- /dev/null +++ b/src/test/ui/borrowck/issue-103624.rs @@ -0,0 +1,31 @@ +// edition:2021 + +struct StructA { + b: StructB, +} + +async fn spawn_blocking<T>(f: impl (Fn() -> T) + Send + Sync + 'static) -> T { + todo!() +} + +impl StructA { + async fn foo(&self) { + let bar = self.b.bar().await; + spawn_blocking(move || { + //~^ ERROR borrowed data escapes outside of associated function + self.b; + //~^ ERROR cannot move out of `self.b`, as `self` is a captured variable in an `Fn` closure + }) + .await; + } +} + +struct StructB {} + +impl StructB { + async fn bar(&self) -> Option<u8> { + None + } +} + +fn main() {} diff --git a/src/test/ui/borrowck/issue-103624.stderr b/src/test/ui/borrowck/issue-103624.stderr new file mode 100644 index 000000000..e6a35dd88 --- /dev/null +++ b/src/test/ui/borrowck/issue-103624.stderr @@ -0,0 +1,35 @@ +error[E0507]: cannot move out of `self.b`, as `self` is a captured variable in an `Fn` closure + --> $DIR/issue-103624.rs:16:13 + | +LL | async fn foo(&self) { + | ----- captured outer variable +LL | let bar = self.b.bar().await; +LL | spawn_blocking(move || { + | ------- captured by this `Fn` closure +LL | +LL | self.b; + | ^^^^^^ move occurs because `self.b` has type `StructB`, which does not implement the `Copy` trait + +error[E0521]: borrowed data escapes outside of associated function + --> $DIR/issue-103624.rs:14:9 + | +LL | async fn foo(&self) { + | ----- + | | + | `self` is a reference that is only valid in the associated function body + | let's call the lifetime of this reference `'1` +LL | let bar = self.b.bar().await; +LL | / spawn_blocking(move || { +LL | | +LL | | self.b; +LL | | +LL | | }) + | | ^ + | | | + | |__________`self` escapes the associated function body here + | argument requires that `'1` must outlive `'static` + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0507, E0521. +For more information about an error, try `rustc --explain E0507`. diff --git a/src/test/ui/issues/issue-17718-static-move.rs b/src/test/ui/borrowck/issue-17718-static-move.rs index 015487a06..015487a06 100644 --- a/src/test/ui/issues/issue-17718-static-move.rs +++ b/src/test/ui/borrowck/issue-17718-static-move.rs diff --git a/src/test/ui/issues/issue-17718-static-move.stderr b/src/test/ui/borrowck/issue-17718-static-move.stderr index 984534bfb..984534bfb 100644 --- a/src/test/ui/issues/issue-17718-static-move.stderr +++ b/src/test/ui/borrowck/issue-17718-static-move.stderr diff --git a/src/test/ui/issues/issue-23338-params-outlive-temps-of-body.rs b/src/test/ui/borrowck/issue-23338-params-outlive-temps-of-body.rs index d45aaa843..d45aaa843 100644 --- a/src/test/ui/issues/issue-23338-params-outlive-temps-of-body.rs +++ b/src/test/ui/borrowck/issue-23338-params-outlive-temps-of-body.rs diff --git a/src/test/ui/borrowck/issue-24267-flow-exit.stderr b/src/test/ui/borrowck/issue-24267-flow-exit.stderr index b85e8f216..58d1c8c0f 100644 --- a/src/test/ui/borrowck/issue-24267-flow-exit.stderr +++ b/src/test/ui/borrowck/issue-24267-flow-exit.stderr @@ -8,6 +8,10 @@ LL | println!("{}", x); | ^ `x` used here but it isn't initialized | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let x: i32 = 0; + | +++ error[E0381]: used binding `x` isn't initialized --> $DIR/issue-24267-flow-exit.rs:18:20 @@ -19,6 +23,10 @@ LL | println!("{}", x); | ^ `x` used here but it isn't initialized | = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let x: i32 = 0; + | +++ error: aborting due to 2 previous errors diff --git a/src/test/ui/borrowck/issue-62107-match-arm-scopes.stderr b/src/test/ui/borrowck/issue-62107-match-arm-scopes.stderr index f5d2eecfa..9683da919 100644 --- a/src/test/ui/borrowck/issue-62107-match-arm-scopes.stderr +++ b/src/test/ui/borrowck/issue-62107-match-arm-scopes.stderr @@ -5,6 +5,11 @@ LL | let e: i32; | - binding declared here but left uninitialized LL | match e { | ^ `e` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let e: i32 = 0; + | +++ error: aborting due to previous error diff --git a/src/test/ui/borrowck/issue-81899.rs b/src/test/ui/borrowck/issue-81899.rs index 9b6061203..24b20b650 100644 --- a/src/test/ui/borrowck/issue-81899.rs +++ b/src/test/ui/borrowck/issue-81899.rs @@ -2,8 +2,7 @@ // The `panic!()` below is important to trigger the fixed ICE. const _CONST: &[u8] = &f(&[], |_| {}); -//~^ ERROR any use of this value -//~| WARNING this was previously +//~^ ERROR constant const fn f<F>(_: &[u8], _: F) -> &[u8] where diff --git a/src/test/ui/borrowck/issue-81899.stderr b/src/test/ui/borrowck/issue-81899.stderr index fd591c7b5..12e80b9df 100644 --- a/src/test/ui/borrowck/issue-81899.stderr +++ b/src/test/ui/borrowck/issue-81899.stderr @@ -1,5 +1,5 @@ error[E0080]: evaluation of constant value failed - --> $DIR/issue-81899.rs:12:5 + --> $DIR/issue-81899.rs:11:5 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | -------------- inside `_CONST` at $DIR/issue-81899.rs:4:24 @@ -7,32 +7,17 @@ LL | const _CONST: &[u8] = &f(&[], |_| {}); LL | panic!() | ^^^^^^^^ | | - | the evaluated program panicked at 'explicit panic', $DIR/issue-81899.rs:12:5 + | the evaluated program panicked at 'explicit panic', $DIR/issue-81899.rs:11:5 | inside `f::<[closure@$DIR/issue-81899.rs:4:31: 4:34]>` at $SRC_DIR/std/src/panic.rs:LL:COL | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) -error: any use of this value will cause an error +error[E0080]: evaluation of constant value failed --> $DIR/issue-81899.rs:4:23 | LL | const _CONST: &[u8] = &f(&[], |_| {}); - | ------------------- ^^^^^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> + | ^^^^^^^^^^^^^^^ referenced constant has errors error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0080`. -Future incompatibility report: Future breakage diagnostic: -error: any use of this value will cause an error - --> $DIR/issue-81899.rs:4:23 - | -LL | const _CONST: &[u8] = &f(&[], |_| {}); - | ------------------- ^^^^^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> - diff --git a/src/test/ui/borrowck/issue-88434-minimal-example.rs b/src/test/ui/borrowck/issue-88434-minimal-example.rs index 7618d001e..983a02310 100644 --- a/src/test/ui/borrowck/issue-88434-minimal-example.rs +++ b/src/test/ui/borrowck/issue-88434-minimal-example.rs @@ -1,8 +1,7 @@ // Regression test related to issue 88434 const _CONST: &() = &f(&|_| {}); -//~^ ERROR any use of this value -//~| WARNING this was previously +//~^ ERROR constant const fn f<F>(_: &F) where diff --git a/src/test/ui/borrowck/issue-88434-minimal-example.stderr b/src/test/ui/borrowck/issue-88434-minimal-example.stderr index a3582e780..dc87c4c2b 100644 --- a/src/test/ui/borrowck/issue-88434-minimal-example.stderr +++ b/src/test/ui/borrowck/issue-88434-minimal-example.stderr @@ -1,5 +1,5 @@ error[E0080]: evaluation of constant value failed - --> $DIR/issue-88434-minimal-example.rs:11:5 + --> $DIR/issue-88434-minimal-example.rs:10:5 | LL | const _CONST: &() = &f(&|_| {}); | ---------- inside `_CONST` at $DIR/issue-88434-minimal-example.rs:3:22 @@ -7,32 +7,17 @@ LL | const _CONST: &() = &f(&|_| {}); LL | panic!() | ^^^^^^^^ | | - | the evaluated program panicked at 'explicit panic', $DIR/issue-88434-minimal-example.rs:11:5 + | the evaluated program panicked at 'explicit panic', $DIR/issue-88434-minimal-example.rs:10:5 | inside `f::<[closure@$DIR/issue-88434-minimal-example.rs:3:25: 3:28]>` at $SRC_DIR/std/src/panic.rs:LL:COL | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) -error: any use of this value will cause an error +error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-minimal-example.rs:3:21 | LL | const _CONST: &() = &f(&|_| {}); - | ----------------- ^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> + | ^^^^^^^^^^^ referenced constant has errors error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0080`. -Future incompatibility report: Future breakage diagnostic: -error: any use of this value will cause an error - --> $DIR/issue-88434-minimal-example.rs:3:21 - | -LL | const _CONST: &() = &f(&|_| {}); - | ----------------- ^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> - diff --git a/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.rs b/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.rs index b1fc1615e..a99c5b76a 100644 --- a/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.rs +++ b/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.rs @@ -1,8 +1,7 @@ // Regression test for issue 88434 const _CONST: &[u8] = &f(&[], |_| {}); -//~^ ERROR any use of this value will cause an error -//~| WARNING this was previously +//~^ ERROR constant const fn f<F>(_: &[u8], _: F) -> &[u8] where diff --git a/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.stderr b/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.stderr index a6c65b302..4b4a25d7b 100644 --- a/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.stderr +++ b/src/test/ui/borrowck/issue-88434-removal-index-should-be-less.stderr @@ -1,5 +1,5 @@ error[E0080]: evaluation of constant value failed - --> $DIR/issue-88434-removal-index-should-be-less.rs:11:5 + --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | -------------- inside `_CONST` at $DIR/issue-88434-removal-index-should-be-less.rs:3:24 @@ -7,32 +7,17 @@ LL | const _CONST: &[u8] = &f(&[], |_| {}); LL | panic!() | ^^^^^^^^ | | - | the evaluated program panicked at 'explicit panic', $DIR/issue-88434-removal-index-should-be-less.rs:11:5 + | the evaluated program panicked at 'explicit panic', $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | inside `f::<[closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34]>` at $SRC_DIR/std/src/panic.rs:LL:COL | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) -error: any use of this value will cause an error +error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:3:23 | LL | const _CONST: &[u8] = &f(&[], |_| {}); - | ------------------- ^^^^^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> + | ^^^^^^^^^^^^^^^ referenced constant has errors error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0080`. -Future incompatibility report: Future breakage diagnostic: -error: any use of this value will cause an error - --> $DIR/issue-88434-removal-index-should-be-less.rs:3:23 - | -LL | const _CONST: &[u8] = &f(&[], |_| {}); - | ------------------- ^^^^^^^^^^^^^^^ referenced constant has errors - | - = note: `#[deny(const_err)]` on by default - = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release! - = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800> - diff --git a/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.rs b/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.rs new file mode 100644 index 000000000..31eba0740 --- /dev/null +++ b/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.rs @@ -0,0 +1,26 @@ +// Tests the suggestion to reborrow the first move site +// when we move then borrow a `&mut` ref. + +struct State; + +impl IntoIterator for &mut State { + type IntoIter = std::vec::IntoIter<()>; + type Item = (); + + fn into_iter(self) -> Self::IntoIter { + vec![].into_iter() + } +} + +fn once(f: impl FnOnce()) {} + +fn fill_memory_blocks_mt(state: &mut State) { + for _ in state {} + //~^ HELP consider creating a fresh reborrow of `state` here + fill_segment(state); + //~^ ERROR borrow of moved value: `state` +} + +fn fill_segment(state: &mut State) {} + +fn main() {} diff --git a/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.stderr b/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.stderr new file mode 100644 index 000000000..13a2005e2 --- /dev/null +++ b/src/test/ui/borrowck/reborrow-sugg-move-then-borrow.stderr @@ -0,0 +1,24 @@ +error[E0382]: borrow of moved value: `state` + --> $DIR/reborrow-sugg-move-then-borrow.rs:20:18 + | +LL | fn fill_memory_blocks_mt(state: &mut State) { + | ----- move occurs because `state` has type `&mut State`, which does not implement the `Copy` trait +LL | for _ in state {} + | ----- `state` moved due to this implicit call to `.into_iter()` +LL | +LL | fill_segment(state); + | ^^^^^ value borrowed here after move + | +note: this function takes ownership of the receiver `self`, which moves `state` + --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL + | +LL | fn into_iter(self) -> Self::IntoIter; + | ^^^^ +help: consider creating a fresh reborrow of `state` here + | +LL | for _ in &mut *state {} + | ++++++ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0382`. diff --git a/src/test/ui/borrowck/suggest-assign-rvalue.rs b/src/test/ui/borrowck/suggest-assign-rvalue.rs new file mode 100644 index 000000000..aaca9d47f --- /dev/null +++ b/src/test/ui/borrowck/suggest-assign-rvalue.rs @@ -0,0 +1,57 @@ +#![allow(dead_code)] +#![feature(never_type)] + +#[derive(Debug, Default)] +struct Demo {} + +#[derive(Debug)] +struct DemoNoDef {} + +fn apple(_: u32) {} + +fn banana() { + let chaenomeles; + apple(chaenomeles); + //~^ ERROR used binding `chaenomeles` isn't initialized [E0381] +} + +fn main() { + let my_bool: bool = bool::default(); + println!("my_bool: {}", my_bool); + + let my_float: f32; + println!("my_float: {}", my_float); + //~^ ERROR used binding `my_float` isn't initialized + let demo: Demo; + println!("demo: {:?}", demo); + //~^ ERROR used binding `demo` isn't initialized + + let demo_no: DemoNoDef; + println!("demo_no: {:?}", demo_no); + //~^ ERROR used binding `demo_no` isn't initialized + + let arr: [i32; 5]; + println!("arr: {:?}", arr); + //~^ ERROR used binding `arr` isn't initialized + let foo: Vec<&str>; + println!("foo: {:?}", foo); + //~^ ERROR used binding `foo` isn't initialized + + let my_string: String; + println!("my_string: {}", my_string); + //~^ ERROR used binding `my_string` isn't initialized + + let my_int: &i32; + println!("my_int: {}", *my_int); + //~^ ERROR used binding `my_int` isn't initialized + + let hello: &str; + println!("hello: {}", hello); + //~^ ERROR used binding `hello` isn't initialized + + let never: !; + println!("never: {}", never); + //~^ ERROR used binding `never` isn't initialized [E0381] + + banana(); +} diff --git a/src/test/ui/borrowck/suggest-assign-rvalue.stderr b/src/test/ui/borrowck/suggest-assign-rvalue.stderr new file mode 100644 index 000000000..92acba640 --- /dev/null +++ b/src/test/ui/borrowck/suggest-assign-rvalue.stderr @@ -0,0 +1,138 @@ +error[E0381]: used binding `chaenomeles` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:14:11 + | +LL | let chaenomeles; + | ----------- binding declared here but left uninitialized +LL | apple(chaenomeles); + | ^^^^^^^^^^^ `chaenomeles` used here but it isn't initialized + | +help: consider assigning a value + | +LL | let chaenomeles = 0; + | +++ + +error[E0381]: used binding `my_float` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:23:30 + | +LL | let my_float: f32; + | -------- binding declared here but left uninitialized +LL | println!("my_float: {}", my_float); + | ^^^^^^^^ `my_float` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let my_float: f32 = 0.0; + | +++++ + +error[E0381]: used binding `demo` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:26:28 + | +LL | let demo: Demo; + | ---- binding declared here but left uninitialized +LL | println!("demo: {:?}", demo); + | ^^^^ `demo` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let demo: Demo = Default::default(); + | ++++++++++++++++++++ + +error[E0381]: used binding `demo_no` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:30:31 + | +LL | let demo_no: DemoNoDef; + | ------- binding declared here but left uninitialized +LL | println!("demo_no: {:?}", demo_no); + | ^^^^^^^ `demo_no` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let demo_no: DemoNoDef = todo!(); + | +++++++++ + +error[E0381]: used binding `arr` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:34:27 + | +LL | let arr: [i32; 5]; + | --- binding declared here but left uninitialized +LL | println!("arr: {:?}", arr); + | ^^^ `arr` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let arr: [i32; 5] = todo!(); + | +++++++++ + +error[E0381]: used binding `foo` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:37:27 + | +LL | let foo: Vec<&str>; + | --- binding declared here but left uninitialized +LL | println!("foo: {:?}", foo); + | ^^^ `foo` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let foo: Vec<&str> = vec![]; + | ++++++++ + +error[E0381]: used binding `my_string` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:41:31 + | +LL | let my_string: String; + | --------- binding declared here but left uninitialized +LL | println!("my_string: {}", my_string); + | ^^^^^^^^^ `my_string` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let my_string: String = Default::default(); + | ++++++++++++++++++++ + +error[E0381]: used binding `my_int` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:45:28 + | +LL | let my_int: &i32; + | ------ binding declared here but left uninitialized +LL | println!("my_int: {}", *my_int); + | ^^^^^^^ `*my_int` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let my_int: &i32 = todo!(); + | +++++++++ + +error[E0381]: used binding `hello` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:49:27 + | +LL | let hello: &str; + | ----- binding declared here but left uninitialized +LL | println!("hello: {}", hello); + | ^^^^^ `hello` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) +help: consider assigning a value + | +LL | let hello: &str = todo!(); + | +++++++++ + +error[E0381]: used binding `never` isn't initialized + --> $DIR/suggest-assign-rvalue.rs:53:27 + | +LL | let never: !; + | ----- binding declared here but left uninitialized +LL | println!("never: {}", never); + | ^^^^^ `never` used here but it isn't initialized + | + = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info) + +error: aborting due to 10 previous errors + +For more information about this error, try `rustc --explain E0381`. diff --git a/src/test/ui/borrowck/two-phase-across-loop.stderr b/src/test/ui/borrowck/two-phase-across-loop.stderr index 95896c6bb..22f9b39df 100644 --- a/src/test/ui/borrowck/two-phase-across-loop.stderr +++ b/src/test/ui/borrowck/two-phase-across-loop.stderr @@ -2,7 +2,10 @@ error[E0499]: cannot borrow `foo` as mutable more than once at a time --> $DIR/two-phase-across-loop.rs:17:22 | LL | strings.push(foo.get_string()); - | ^^^^^^^^^^^^^^^^ `foo` was mutably borrowed here in the previous iteration of the loop + | -------------^^^^^^^^^^^^^^^^- + | | | + | | `foo` was mutably borrowed here in the previous iteration of the loop + | first borrow used here, in later iteration of loop error: aborting due to previous error |