Do not suggest conversion method that is already there

This commit is contained in:
Esteban Küber 2018-08-15 12:30:50 -07:00
parent 0f4b4987cd
commit 5a0a38a46f
3 changed files with 46 additions and 2 deletions

View File

@ -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::<Vec<_>>();
.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::<Vec<_>>();
if !suggestions.is_empty() {
err.span_suggestions(expr.span, "try using a conversion method", suggestions);
}

View File

@ -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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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::<Vec<_>>();
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);
}
}

View File

@ -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`.