diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs index 3b7d31b1b13bd..d0e014971f442 100644 --- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs @@ -3229,8 +3229,20 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> { Applicability::MaybeIncorrect, ); } + + let mutability = if matches!(borrow.kind(), BorrowKind::Mut { .. }) { + "mut " + } else { + "" + }; + if !is_format_arguments_item { - let addition = format!("let binding = {};\n{}", s, " ".repeat(p)); + let addition = format!( + "let {}binding = {};\n{}", + mutability, + s, + " ".repeat(p) + ); err.multipart_suggestion_verbose( msg, vec![ diff --git a/tests/ui/coroutine/auto-trait-regions.stderr b/tests/ui/coroutine/auto-trait-regions.stderr index a9a0bde2ba019..a3b5a5f006e61 100644 --- a/tests/ui/coroutine/auto-trait-regions.stderr +++ b/tests/ui/coroutine/auto-trait-regions.stderr @@ -11,7 +11,7 @@ LL | assert_foo(a); | help: consider using a `let` binding to create a longer lived value | -LL ~ let binding = true; +LL ~ let mut binding = true; LL ~ let a = A(&mut binding, &mut true, No); | @@ -28,7 +28,7 @@ LL | assert_foo(a); | help: consider using a `let` binding to create a longer lived value | -LL ~ let binding = true; +LL ~ let mut binding = true; LL ~ let a = A(&mut true, &mut binding, No); | diff --git a/tests/ui/nll/sugg-mut-for-binding-issue-137486.fixed b/tests/ui/nll/sugg-mut-for-binding-issue-137486.fixed new file mode 100644 index 0000000000000..ee9d9a373de00 --- /dev/null +++ b/tests/ui/nll/sugg-mut-for-binding-issue-137486.fixed @@ -0,0 +1,23 @@ +//@ run-rustfix +#![allow(unused_assignments)] + +use std::pin::Pin; +fn main() { + let mut s = String::from("hello"); + let mut ref_s = &mut s; + + let mut binding = String::from("world"); + ref_s = &mut binding; //~ ERROR temporary value dropped while borrowed [E0716] + + print!("r1 = {}", ref_s); + + let mut val: u8 = 5; + let mut s = Pin::new(&mut val); + let mut ref_s = &mut s; + + let mut val2: u8 = 10; + let mut binding = Pin::new(&mut val2); + ref_s = &mut binding; //~ ERROR temporary value dropped while borrowed [E0716] + + print!("r1 = {}", ref_s); +} diff --git a/tests/ui/nll/sugg-mut-for-binding-issue-137486.rs b/tests/ui/nll/sugg-mut-for-binding-issue-137486.rs new file mode 100644 index 0000000000000..8f7ea7561077d --- /dev/null +++ b/tests/ui/nll/sugg-mut-for-binding-issue-137486.rs @@ -0,0 +1,21 @@ +//@ run-rustfix +#![allow(unused_assignments)] + +use std::pin::Pin; +fn main() { + let mut s = String::from("hello"); + let mut ref_s = &mut s; + + ref_s = &mut String::from("world"); //~ ERROR temporary value dropped while borrowed [E0716] + + print!("r1 = {}", ref_s); + + let mut val: u8 = 5; + let mut s = Pin::new(&mut val); + let mut ref_s = &mut s; + + let mut val2: u8 = 10; + ref_s = &mut Pin::new(&mut val2); //~ ERROR temporary value dropped while borrowed [E0716] + + print!("r1 = {}", ref_s); +} diff --git a/tests/ui/nll/sugg-mut-for-binding-issue-137486.stderr b/tests/ui/nll/sugg-mut-for-binding-issue-137486.stderr new file mode 100644 index 0000000000000..8432725f60ad3 --- /dev/null +++ b/tests/ui/nll/sugg-mut-for-binding-issue-137486.stderr @@ -0,0 +1,37 @@ +error[E0716]: temporary value dropped while borrowed + --> $DIR/sugg-mut-for-binding-issue-137486.rs:9:18 + | +LL | ref_s = &mut String::from("world"); + | ^^^^^^^^^^^^^^^^^^^^^- temporary value is freed at the end of this statement + | | + | creates a temporary value which is freed while still in use +LL | +LL | print!("r1 = {}", ref_s); + | ----- borrow later used here + | +help: consider using a `let` binding to create a longer lived value + | +LL ~ let mut binding = String::from("world"); +LL ~ ref_s = &mut binding; + | + +error[E0716]: temporary value dropped while borrowed + --> $DIR/sugg-mut-for-binding-issue-137486.rs:18:18 + | +LL | ref_s = &mut Pin::new(&mut val2); + | ^^^^^^^^^^^^^^^^^^^- temporary value is freed at the end of this statement + | | + | creates a temporary value which is freed while still in use +LL | +LL | print!("r1 = {}", ref_s); + | ----- borrow later used here + | +help: consider using a `let` binding to create a longer lived value + | +LL ~ let mut binding = Pin::new(&mut val2); +LL ~ ref_s = &mut binding; + | + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0716`.