rust/tests/ui/borrowck/borrowck-uninit-ref-chain.rs

struct S<X, Y> {
    x: X,
    y: Y,
}

fn main() {
    let x: &&Box<i32>;
    let _y = &**x; //~ ERROR [E0381]

    let x: &&S<i32, i32>;
    let _y = &**x; //~ ERROR [E0381]

    let x: &&i32;
    let _y = &**x; //~ ERROR [E0381]


    let mut a: S<i32, i32>;
    a.x = 0; //~ ERROR [E0381]
    let _b = &a.x;

    let mut a: S<&&i32, &&i32>;
    a.x = &&0; //~ ERROR [E0381]
    let _b = &**a.x;


    let mut a: S<i32, i32>;
    a.x = 0; //~ ERROR [E0381]
    let _b = &a.y;

    let mut a: S<&&i32, &&i32>;
    a.x = &&0; //~ ERROR [E0381]
    let _b = &**a.y;
}
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00			`struct S<X, Y> {`
			`x: X,`
			`y: Y,`
			`}`

			`fn main() {`
			`let x: &&Box<i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`let _y = &**x; //~ ERROR [E0381]`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00
			`let x: &&S<i32, i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`let _y = &**x; //~ ERROR [E0381]`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00
			`let x: &&i32;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`let _y = &**x; //~ ERROR [E0381]`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00

			`let mut a: S<i32, i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`a.x = 0; //~ ERROR [E0381]`
update tests for migrate mode by default 2019-04-22 07:40:08 +00:00			`let _b = &a.x;`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00
			`let mut a: S<&&i32, &&i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`a.x = &&0; //~ ERROR [E0381]`
update tests for migrate mode by default 2019-04-22 07:40:08 +00:00			`let _b = &**a.x;`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00

			`let mut a: S<i32, i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`a.x = 0; //~ ERROR [E0381]`
update tests for migrate mode by default 2019-04-22 07:40:08 +00:00			`let _b = &a.y;`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00
			`let mut a: S<&&i32, &&i32>;`
On partial uninit error point at where we need init When a binding is declared without a value, borrowck verifies that all codepaths have one assignment to them to initialize them fully. If there are any cases where a condition can be met that leaves the binding uninitialized or we attempt to initialize a field of an unitialized binding, we emit E0381. We now look at all the statements that initialize the binding, and use them to explore branching code paths that don't and point at them. If we find no potential places where an assignment to the binding might be missing, we display the spans of all the existing initializers to provide some context. 2022-06-21 18:57:45 +00:00			`a.x = &&0; //~ ERROR [E0381]`
update tests for migrate mode by default 2019-04-22 07:40:08 +00:00			`let _b = &**a.y;`
Test case illustrating some variants of the issue pointed out by ariel. Expanded to cover partial-initialization ideas. 2017-10-05 12:32:05 +00:00			`}`