diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 8f66c1a2b8cf6..208db8391441c 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -2919,7 +2919,10 @@ impl<'a> Parser<'a> { let op_span = mk_sp(op.span.lo, self.span.hi); let mut err = self.diagnostic().struct_span_err(op_span, "chained comparison operators require parentheses"); - if op.node == BinOpKind::Lt && *outer_op == AssocOp::Greater { + if op.node == BinOpKind::Lt && + *outer_op == AssocOp::Less || // Include `<` to provide this recommendation + *outer_op == AssocOp::Greater // even in a case like the following: + { // Foo>> err.help( "use `::<...>` instead of `<...>` if you meant to specify type arguments"); } diff --git a/src/test/ui/did_you_mean/issue-40396.rs b/src/test/ui/did_you_mean/issue-40396.rs new file mode 100644 index 0000000000000..1eae180976ad3 --- /dev/null +++ b/src/test/ui/did_you_mean/issue-40396.rs @@ -0,0 +1,23 @@ +// Copyright 2017 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 foo() { + println!("{:?}", (0..13).collect>()); +} + +fn bar() { + println!("{:?}", Vec::new()); +} + +fn qux() { + println!("{:?}", (0..13).collect()); +} + +fn main() {} diff --git a/src/test/ui/did_you_mean/issue-40396.stderr b/src/test/ui/did_you_mean/issue-40396.stderr new file mode 100644 index 0000000000000..1a0c74dc01a09 --- /dev/null +++ b/src/test/ui/did_you_mean/issue-40396.stderr @@ -0,0 +1,34 @@ +error: chained comparison operators require parentheses + --> $DIR/issue-40396.rs:12:37 + | +12 | println!("{:?}", (0..13).collect>()); + | ^^^^^^^^ + | + = help: use `::<...>` instead of `<...>` if you meant to specify type arguments + +error: chained comparison operators require parentheses + --> $DIR/issue-40396.rs:16:25 + | +16 | println!("{:?}", Vec::new()); + | ^^^^^^^ + | + = help: use `::<...>` instead of `<...>` if you meant to specify type arguments + +error: chained comparison operators require parentheses + --> $DIR/issue-40396.rs:20:37 + | +20 | println!("{:?}", (0..13).collect()); + | ^^^^^^^^ + | + = help: use `::<...>` instead of `<...>` if you meant to specify type arguments + +error: chained comparison operators require parentheses + --> $DIR/issue-40396.rs:20:41 + | +20 | println!("{:?}", (0..13).collect()); + | ^^^^^^ + | + = help: use `::<...>` instead of `<...>` if you meant to specify type arguments + +error: aborting due to 4 previous errors +