add hint to fix error for immutable ref in arg
This commit is contained in:
Mikhail Modin
parent
0b399e5e99
commit
67a24c2e18
15 changed files with 342 additions and 46 deletions
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@ -24,7 +24,7 @@ use self::InteriorKind::*;
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use rustc::dep_graph::DepNode;
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use rustc::hir::map as hir_map;
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use rustc::hir::map::blocks::FnParts;
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use rustc::hir::map::blocks::{FnParts, FnLikeNode};
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use rustc::cfg;
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use rustc::middle::dataflow::DataFlowContext;
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use rustc::middle::dataflow::BitwiseOperator;
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@ -970,51 +970,8 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
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pub fn note_and_explain_bckerr(&self, db: &mut DiagnosticBuilder, err: BckError<'tcx>,
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error_span: Span) {
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let code = err.code;
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match code {
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err_mutbl => {
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match err.cmt.note {
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mc::NoteClosureEnv(upvar_id) | mc::NoteUpvarRef(upvar_id) => {
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// If this is an `Fn` closure, it simply can't mutate upvars.
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// If it's an `FnMut` closure, the original variable was declared immutable.
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// We need to determine which is the case here.
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let kind = match err.cmt.upvar().unwrap().cat {
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Categorization::Upvar(mc::Upvar { kind, .. }) => kind,
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_ => bug!()
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};
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if kind == ty::ClosureKind::Fn {
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db.span_help(
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self.tcx.map.span(upvar_id.closure_expr_id),
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"consider changing this closure to take \
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self by mutable reference");
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}
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}
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_ => {
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if let Categorization::Local(local_id) = err.cmt.cat {
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let span = self.tcx.map.span(local_id);
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if let Ok(snippet) = self.tcx.sess.codemap().span_to_snippet(span) {
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if snippet.starts_with("ref mut ") || snippet.starts_with("&mut ") {
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db.span_label(error_span, &format!("cannot reborrow mutably"));
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db.span_label(error_span, &format!("try removing `&mut` here"));
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} else {
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if snippet.starts_with("ref ") {
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db.span_label(span,
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&format!("use `{}` here to make mutable",
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snippet.replace("ref ", "ref mut ")));
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} else if snippet != "self" {
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db.span_label(span,
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&format!("use `mut {}` here to make mutable", snippet));
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}
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db.span_label(error_span, &format!("cannot borrow mutably"));
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}
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} else {
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db.span_label(error_span, &format!("cannot borrow mutably"));
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}
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}
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}
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}
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}
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match err.code {
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err_mutbl => self.note_and_explain_mutbl_error(db, &err, &error_span),
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err_out_of_scope(super_scope, sub_scope, cause) => {
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let (value_kind, value_msg) = match err.cmt.cat {
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mc::Categorization::Rvalue(_) =>
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@ -1135,6 +1092,86 @@ impl<'a, 'tcx> BorrowckCtxt<'a, 'tcx> {
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}
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}
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fn note_and_explain_mutbl_error(&self, db: &mut DiagnosticBuilder, err: &BckError<'tcx>,
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error_span: &Span) {
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match err.cmt.note {
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mc::NoteClosureEnv(upvar_id) | mc::NoteUpvarRef(upvar_id) => {
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// If this is an `Fn` closure, it simply can't mutate upvars.
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// If it's an `FnMut` closure, the original variable was declared immutable.
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// We need to determine which is the case here.
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let kind = match err.cmt.upvar().unwrap().cat {
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Categorization::Upvar(mc::Upvar { kind, .. }) => kind,
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_ => bug!()
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};
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if kind == ty::ClosureKind::Fn {
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db.span_help(self.tcx.map.span(upvar_id.closure_expr_id),
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"consider changing this closure to take \
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self by mutable reference");
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}
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}
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_ => {
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if let Categorization::Deref(ref inner_cmt, ..) = err.cmt.cat {
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if let Categorization::Local(local_id) = inner_cmt.cat {
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let parent = self.tcx.map.get_parent_node(local_id);
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let opt_fn_decl = FnLikeNode::from_node(self.tcx.map.get(parent))
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.map(|fn_like| fn_like.decl());
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if let Some(fn_decl) = opt_fn_decl {
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if let Some(ref arg) = fn_decl.inputs.iter()
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.find(|ref arg| arg.pat.id == local_id) {
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if let hir::TyRptr(
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opt_lifetime,
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hir::MutTy{mutbl: hir::Mutability::MutImmutable, ref ty}) =
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arg.ty.node {
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if let Some(lifetime) = opt_lifetime {
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if let Ok(snippet) = self.tcx.sess.codemap()
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.span_to_snippet(ty.span) {
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if let Ok(lifetime_snippet) = self.tcx.sess.codemap()
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.span_to_snippet(lifetime.span) {
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db.span_label(arg.ty.span,
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&format!("use `&{} mut {}` \
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here to make mutable",
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lifetime_snippet,
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snippet));
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}
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}
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}
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else if let Ok(snippet) = self.tcx.sess.codemap()
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.span_to_snippet(arg.ty.span) {
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if snippet.starts_with("&") {
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db.span_label(arg.ty.span,
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&format!("use `{}` here to make mutable",
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snippet.replace("&", "&mut ")));
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}
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}
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}
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}
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}
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}
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} else if let Categorization::Local(local_id) = err.cmt.cat {
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let span = self.tcx.map.span(local_id);
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if let Ok(snippet) = self.tcx.sess.codemap().span_to_snippet(span) {
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if snippet.starts_with("ref mut ") || snippet.starts_with("&mut ") {
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db.span_label(*error_span, &format!("cannot reborrow mutably"));
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db.span_label(*error_span, &format!("try removing `&mut` here"));
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} else {
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if snippet.starts_with("ref ") {
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db.span_label(span, &format!("use `{}` here to make mutable",
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snippet.replace("ref ", "ref mut ")));
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} else if snippet != "self" {
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db.span_label(span,
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&format!("use `mut {}` here to make mutable",
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snippet));
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}
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db.span_label(*error_span, &format!("cannot borrow mutably"));
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}
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} else {
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db.span_label(*error_span, &format!("cannot borrow mutably"));
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}
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}
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}
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}
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}
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pub fn append_loan_path_to_string(&self,
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loan_path: &LoanPath<'tcx>,
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out: &mut String) {
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@ -0,0 +1,86 @@
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:63:24
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62 | fn deref_mut_field1(x: Own<Point>) {
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| - use `mut x` here to make mutable
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63 | let __isize = &mut x.y; //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:75:10
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74 | fn deref_extend_mut_field1(x: &Own<Point>) -> &mut isize {
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| ----------- use `&mut Own<Point>` here to make mutable
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75 | &mut x.y //~ ERROR cannot borrow
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| ^
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error[E0499]: cannot borrow `*x` as mutable more than once at a time
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:88:19
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87 | let _x = &mut x.x;
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| - first mutable borrow occurs here
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88 | let _y = &mut x.y; //~ ERROR cannot borrow
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| ^ second mutable borrow occurs here
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89 | }
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| - first borrow ends here
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:98:5
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97 | fn assign_field1<'a>(x: Own<Point>) {
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| - use `mut x` here to make mutable
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98 | x.y = 3; //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:102:5
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101 | fn assign_field2<'a>(x: &'a Own<Point>) {
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| -------------- use `&'a mut Own<Point>` here to make mutable
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102 | x.y = 3; //~ ERROR cannot borrow
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| ^
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error[E0499]: cannot borrow `*x` as mutable more than once at a time
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:111:5
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110 | let _p: &mut Point = &mut **x;
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| -- first mutable borrow occurs here
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111 | x.y = 3; //~ ERROR cannot borrow
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| ^ second mutable borrow occurs here
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112 | }
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| - first borrow ends here
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:119:5
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118 | fn deref_mut_method1(x: Own<Point>) {
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| - use `mut x` here to make mutable
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119 | x.set(0, 0); //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:131:5
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130 | fn deref_extend_mut_method1(x: &Own<Point>) -> &mut isize {
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| ----------- use `&mut Own<Point>` here to make mutable
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131 | x.y_mut() //~ ERROR cannot borrow
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| ^
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:139:6
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138 | fn assign_method1<'a>(x: Own<Point>) {
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| - use `mut x` here to make mutable
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139 | *x.y_mut() = 3; //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:143:6
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142 | fn assign_method2<'a>(x: &'a Own<Point>) {
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| -------------- use `&'a mut Own<Point>` here to make mutable
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143 | *x.y_mut() = 3; //~ ERROR cannot borrow
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| ^
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error: aborting due to 10 previous errors
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34
src/test/ui/span/borrowck-borrow-overloaded-deref-mut.stderr
Normal file
34
src/test/ui/span/borrowck-borrow-overloaded-deref-mut.stderr
Normal file
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@ -0,0 +1,34 @@
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-deref-mut.rs:39:25
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38 | fn deref_mut1(x: Own<isize>) {
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| - use `mut x` here to make mutable
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39 | let __isize = &mut *x; //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-deref-mut.rs:51:11
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50 | fn deref_extend_mut1<'a>(x: &'a Own<isize>) -> &'a mut isize {
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| -------------- use `&'a mut Own<isize>` here to make mutable
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51 | &mut **x //~ ERROR cannot borrow
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| ^^
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error: cannot borrow immutable argument `x` as mutable
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--> $DIR/borrowck-borrow-overloaded-deref-mut.rs:59:6
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58 | fn assign1<'a>(x: Own<isize>) {
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| - use `mut x` here to make mutable
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59 | *x = 3; //~ ERROR cannot borrow
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| ^ cannot borrow mutably
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-borrow-overloaded-deref-mut.rs:63:6
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62 | fn assign2<'a>(x: &'a Own<isize>) {
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| -------------- use `&'a mut Own<isize>` here to make mutable
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63 | **x = 3; //~ ERROR cannot borrow
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| ^^
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error: aborting due to 4 previous errors
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43
src/test/ui/span/borrowck-call-is-borrow-issue-12224.stderr
Normal file
43
src/test/ui/span/borrowck-call-is-borrow-issue-12224.stderr
Normal file
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@ -0,0 +1,43 @@
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error[E0499]: cannot borrow `f` as mutable more than once at a time
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--> $DIR/borrowck-call-is-borrow-issue-12224.rs:23:16
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23 | f(Box::new(|| {
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| - ^^ second mutable borrow occurs here
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| |
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| first mutable borrow occurs here
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24 | //~^ ERROR: cannot borrow `f` as mutable more than once
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25 | f((Box::new(|| {})))
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| - borrow occurs due to use of `f` in closure
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26 | }));
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| - first borrow ends here
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error: cannot borrow immutable borrowed content `*f` as mutable
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--> $DIR/borrowck-call-is-borrow-issue-12224.rs:36:5
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35 | fn test2<F>(f: &F) where F: FnMut() {
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| -- use `&mut F` here to make mutable
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36 | (*f)(); //~ ERROR: cannot borrow immutable borrowed content `*f` as mutable
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| ^^^^
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error: cannot borrow immutable `Box` content `*f.f` as mutable
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--> $DIR/borrowck-call-is-borrow-issue-12224.rs:44:5
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44 | f.f.call_mut(()) //~ ERROR: cannot borrow immutable `Box` content `*f.f` as mutable
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| ^^^
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error[E0504]: cannot move `f` into closure because it is borrowed
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--> $DIR/borrowck-call-is-borrow-issue-12224.rs:63:13
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62 | f(Box::new(|a| {
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| - borrow of `f` occurs here
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63 | foo(f);
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| ^ move into closure occurs here
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error[E0507]: cannot move out of captured outer variable in an `FnMut` closure
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--> $DIR/borrowck-call-is-borrow-issue-12224.rs:63:13
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63 | foo(f);
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| ^ cannot move out of captured outer variable in an `FnMut` closure
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error: aborting due to 5 previous errors
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@ -0,0 +1,11 @@
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-call-method-from-mut-aliasable.rs:27:5
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25 | fn b(x: &Foo) {
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| ---- use `&mut Foo` here to make mutable
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26 | x.f();
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27 | x.h(); //~ ERROR cannot borrow
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| ^
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error: aborting due to previous error
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10
src/test/ui/span/borrowck-fn-in-const-b.stderr
Normal file
10
src/test/ui/span/borrowck-fn-in-const-b.stderr
Normal file
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@ -0,0 +1,10 @@
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-fn-in-const-b.rs:17:9
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16 | fn broken(x: &Vec<String>) {
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| ------------ use `&mut Vec<String>` here to make mutable
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17 | x.push(format!("this is broken"));
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| ^
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error: aborting due to previous error
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17
src/test/ui/span/borrowck-object-mutability.stderr
Normal file
17
src/test/ui/span/borrowck-object-mutability.stderr
Normal file
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@ -0,0 +1,17 @@
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error: cannot borrow immutable borrowed content `*x` as mutable
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--> $DIR/borrowck-object-mutability.rs:19:5
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|
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17 | fn borrowed_receiver(x: &Foo) {
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| ---- use `&mut Foo` here to make mutable
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18 | x.borrowed();
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19 | x.borrowed_mut(); //~ ERROR cannot borrow
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| ^
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error: cannot borrow immutable `Box` content `*x` as mutable
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--> $DIR/borrowck-object-mutability.rs:29:5
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|
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29 | x.borrowed_mut(); //~ ERROR cannot borrow
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| ^
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error: aborting due to 2 previous errors
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32
src/test/ui/span/mut-arg-hint.rs
Normal file
32
src/test/ui/span/mut-arg-hint.rs
Normal file
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@ -0,0 +1,32 @@
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// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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trait B {
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fn foo(mut a: &String) {
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a.push_str("bar");
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}
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}
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pub fn foo<'a>(mut a: &'a String) {
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a.push_str("foo");
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}
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struct A {}
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impl A {
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pub fn foo(mut a: &String) {
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a.push_str("foo");
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}
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}
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fn main() {
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foo(&"a".to_string());
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A::foo(&"a".to_string());
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}
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26
src/test/ui/span/mut-arg-hint.stderr
Normal file
26
src/test/ui/span/mut-arg-hint.stderr
Normal file
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@ -0,0 +1,26 @@
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error: cannot borrow immutable borrowed content `*a` as mutable
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--> $DIR/mut-arg-hint.rs:13:9
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|
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12 | fn foo(mut a: &String) {
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| ------- use `&mut String` here to make mutable
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13 | a.push_str("bar");
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| ^
|
||||
|
||||
error: cannot borrow immutable borrowed content `*a` as mutable
|
||||
--> $DIR/mut-arg-hint.rs:18:5
|
||||
|
|
||||
17 | pub fn foo<'a>(mut a: &'a String) {
|
||||
| ---------- use `&'a mut String` here to make mutable
|
||||
18 | a.push_str("foo");
|
||||
| ^
|
||||
|
||||
error: cannot borrow immutable borrowed content `*a` as mutable
|
||||
--> $DIR/mut-arg-hint.rs:25:9
|
||||
|
|
||||
24 | pub fn foo(mut a: &String) {
|
||||
| ------- use `&mut String` here to make mutable
|
||||
25 | a.push_str("foo");
|
||||
| ^
|
||||
|
||||
error: aborting due to 3 previous errors
|
||||
|
||||
Loading…
Add table
Reference in a new issue