rust/tests/ui/parser/bare-struct-body.rs

struct Foo {
    val: (),
}

fn foo() -> Foo { //~ ERROR struct literal body without path
    val: (),
}

fn main() {
    let x = foo();
    x.val == 42; //~ ERROR mismatched types
    let x = { //~ ERROR struct literal body without path
        val: (),
    };
}
Detect blocks that could be struct expr bodies This approach lives exclusively in the parser, so struct expr bodies that are syntactically correct on their own but are otherwise incorrect will still emit confusing errors, like in the following case: ```rust fn foo() -> Foo { bar: Vec::new() } ``` ``` error[E0425]: cannot find value `bar` in this scope --> src/file.rs:5:5 \| 5 \| bar: Vec::new() \| ^^^ expecting a type here because of type ascription error[E0214]: parenthesized type parameters may only be used with a `Fn` trait --> src/file.rs:5:15 \| 5 \| bar: Vec::new() \| ^^^^^ only `Fn` traits may use parentheses error[E0107]: wrong number of type arguments: expected 1, found 0 --> src/file.rs:5:10 \| 5 \| bar: Vec::new() \| ^^^^^^^^^^ expected 1 type argument ``` If that field had a trailing comma, that would be a parse error and it would trigger the new, more targetted, error: ``` error: struct literal body without path --> file.rs:4:17 \| 4 \| fn foo() -> Foo { \| _________________^ 5 \| \| bar: Vec::new(), 6 \| \| } \| \|_^ \| help: you might have forgotten to add the struct literal inside the block \| 4 \| fn foo() -> Foo { Path { 5 \| bar: Vec::new(), 6 \| } } \| ``` Partially address last part of #34255. 2020-08-12 22:39:15 +00:00			`struct Foo {`
			`val: (),`
			`}`

			`fn foo() -> Foo { //~ ERROR struct literal body without path`
			`val: (),`
			`}`

			`fn main() {`
			`let x = foo();`
			`x.val == 42; //~ ERROR mismatched types`
			`let x = { //~ ERROR struct literal body without path`
			`val: (),`
			`};`
			`}`