diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs index 43edb23504480..4fac11189a400 100644 --- a/src/librustc_typeck/check/mod.rs +++ b/src/librustc_typeck/check/mod.rs @@ -4629,8 +4629,14 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let methods = self.get_conversion_methods(expr.span, expected, found); if let Ok(expr_text) = self.sess().codemap().span_to_snippet(expr.span) { let suggestions = iter::repeat(expr_text).zip(methods.iter()) - .map(|(receiver, method)| format!("{}.{}()", receiver, method.ident)) - .collect::>(); + .filter_map(|(receiver, method)| { + let method_call = format!(".{}()", method.ident); + if receiver.ends_with(&method_call) { + None // do not suggest code that is already there (#53348) + } else { + Some(format!("{}{}", receiver, method_call)) + } + }) .collect::>(); if !suggestions.is_empty() { err.span_suggestions(expr.span, "try using a conversion method", suggestions); } diff --git a/src/test/ui/issues/issue-53348.rs b/src/test/ui/issues/issue-53348.rs new file mode 100644 index 0000000000000..46ab07dad6e47 --- /dev/null +++ b/src/test/ui/issues/issue-53348.rs @@ -0,0 +1,26 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +fn main() { + let mut v = vec!["hello", "this", "is", "a", "test"]; + + let v2 = Vec::new(); + + v.into_iter().map(|s|s.to_owned()).collect::>(); + + let mut a = String::new(); + for i in v { + a = *i.to_string(); + //~^ ERROR mismatched types + //~| NOTE expected struct `std::string::String`, found str + //~| NOTE expected type + v2.push(a); + } +} diff --git a/src/test/ui/issues/issue-53348.stderr b/src/test/ui/issues/issue-53348.stderr new file mode 100644 index 0000000000000..9aab4928ffa57 --- /dev/null +++ b/src/test/ui/issues/issue-53348.stderr @@ -0,0 +1,12 @@ +error[E0308]: mismatched types + --> $DIR/issue-53348.rs:20:13 + | +LL | a = *i.to_string(); + | ^^^^^^^^^^^^^^ expected struct `std::string::String`, found str + | + = note: expected type `std::string::String` + found type `str` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`.