remove a type string comparison in check_str_addition

This commit is contained in:
Takayuki Maeda 2022-07-20 07:07:18 +09:00
parent 475aec1188
commit 35118568a6

View File

@ -631,18 +631,19 @@ fn check_str_addition(
let rm_borrow_msg = "remove the borrow to obtain an owned `String`";
let to_owned_msg = "create an owned `String` from a string reference";
let string_type = self.tcx.get_diagnostic_item(sym::String);
let is_std_string = |ty: Ty<'tcx>| match ty.ty_adt_def() {
Some(ty_def) => Some(ty_def.did()) == string_type,
None => false,
let is_std_string = |ty: Ty<'tcx>| {
ty.ty_adt_def()
.map_or(false, |ty_def| self.tcx.is_diagnostic_item(sym::String, ty_def.did()))
};
match (lhs_ty.kind(), rhs_ty.kind()) {
(&Ref(_, l_ty, _), &Ref(_, r_ty, _)) // &str or &String + &str, &String or &&str
if (*l_ty.kind() == Str || is_std_string(l_ty)) && (
*r_ty.kind() == Str || is_std_string(r_ty) ||
&format!("{:?}", rhs_ty) == "&&str"
) =>
if (*l_ty.kind() == Str || is_std_string(l_ty))
&& (*r_ty.kind() == Str
|| is_std_string(r_ty)
|| matches!(
r_ty.kind(), Ref(_, inner_ty, _) if *inner_ty.kind() == Str
)) =>
{
if let IsAssign::No = is_assign { // Do not supply this message if `&str += &str`
err.span_label(op.span, "`+` cannot be used to concatenate two `&str` strings");