src/test/ui/typeck/typeck_type_placeholder_item.rs

// This test checks that it is not possible to enable global type
// inference by using the `_` type placeholder.

fn test() -> _ { 5 }
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

fn test2() -> (_, _) { (5, 5) }
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
//~^^ ERROR the type placeholder `_` is not allowed within types on item signatures

static TEST3: _ = "test";
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

static TEST4: _ = 145;
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

static TEST5: (_, _) = (1, 2);
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures
//~^^ ERROR the type placeholder `_` is not allowed within types on item signatures

fn test6(_: _) { }
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

fn test7(x: _) { let _x: usize = x; }
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

fn test8(_f: fn() -> _) { }
//~^ ERROR the type placeholder `_` is not allowed within types on item signatures

struct Test9;

impl Test9 {
    fn test9(&self) -> _ { () }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn test10(&self, _x : _) { }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
}

impl Clone for Test9 {
    fn clone(&self) -> _ { Test9 }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn clone_from(&mut self, other: _) { *self = Test9; }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
}

struct Test10 {
    a: _,
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    b: (_, _),
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    //~^^ ERROR the type placeholder `_` is not allowed within types on item signatures
}

pub fn main() {
    fn fn_test() -> _ { 5 }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn fn_test2() -> (_, _) { (5, 5) }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    //~^^ ERROR the type placeholder `_` is not allowed within types on item signatures

    static FN_TEST3: _ = "test";
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    static FN_TEST4: _ = 145;
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    static FN_TEST5: (_, _) = (1, 2);
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    //~^^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn fn_test6(_: _) { }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn fn_test7(x: _) { let _x: usize = x; }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    fn fn_test8(_f: fn() -> _) { }
    //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

    struct FnTest9;

    impl FnTest9 {
        fn fn_test9(&self) -> _ { () }
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

        fn fn_test10(&self, _x : _) { }
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    }

    impl Clone for FnTest9 {
        fn clone(&self) -> _ { FnTest9 }
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures

        fn clone_from(&mut self, other: _) { *self = FnTest9; }
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
    }

    struct FnTest10 {
        a: _,
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
        b: (_, _),
        //~^ ERROR the type placeholder `_` is not allowed within types on item signatures
        //~^^ ERROR the type placeholder `_` is not allowed within types on item signatures
    }

}