rust/src/test/ui/stability-attribute/generics-default-stability.rs

// ignore-tidy-linelength
// aux-build:unstable_generic_param.rs

extern crate unstable_generic_param;

use unstable_generic_param::*;

struct R;

impl Trait1 for S {
    fn foo() -> () { () } // ok
}

struct S;

impl Trait1<usize> for S { //~ ERROR use of unstable library feature 'unstable_default'
    fn foo() -> usize { 0 }
}

impl Trait1<isize> for S { //~ ERROR use of unstable library feature 'unstable_default'
    fn foo() -> isize { 0 }
}

impl Trait2<usize> for S { //~ ERROR use of unstable library feature 'unstable_default'
    fn foo() -> usize { 0 }
}

impl Trait3<usize> for S {
    fn foo() -> usize { 0 } // ok
}

fn main() {
    let _ = S;

    let _: Struct1<isize> = Struct1 { field: 1 }; //~ ERROR use of unstable library feature 'unstable_default'

    let _ = STRUCT1; // ok
    let _: Struct1 = STRUCT1; // ok
    let _: Struct1<usize> = STRUCT1; //~ ERROR use of unstable library feature 'unstable_default'
    let _: Struct1<isize> = Struct1 { field: 0 }; //~ ERROR use of unstable library feature 'unstable_default'

    // Instability is not enforced for generic type parameters used in public fields.
    // Note how the unstable type default `usize` leaks,
    // and can be used without the 'unstable_default' feature.
    let _ = STRUCT1.field;
    let _ = Struct1 { field: 1 };
    let _: Struct1 = Struct1 { field: 1 };
    let _: usize = STRUCT1.field;
    let _ = STRUCT1.field + 1;
    let _ = STRUCT1.field + 1usize;

    let _ = Struct2 { field: 1 }; // ok
    let _: Struct2 = Struct2 { field: 1 }; // ok
    let _: Struct2<usize> = Struct2 { field: 1 }; // ok

    let _ = STRUCT2;
    let _: Struct2 = STRUCT2; // ok
    let _: Struct2<usize> = STRUCT2; // ok
    let _: Struct2<isize> = Struct2 { field: 0 }; // ok
    let _ = STRUCT2.field; // ok
    let _: usize = STRUCT2.field; // ok
    let _ = STRUCT2.field + 1; // ok
    let _ = STRUCT2.field + 1usize; // ok

    let _ = STRUCT3;
    let _: Struct3 = STRUCT3; // ok
    let _: Struct3<isize, usize> = STRUCT3; //~ ERROR use of unstable library feature 'unstable_default'
    let _: Struct3<isize> = STRUCT3; // ok
    let _: Struct3<isize, isize> = Struct3 { field1: 0, field2: 0 }; //~ ERROR use of unstable library feature 'unstable_default'
    let _: Struct3<usize, usize> = Struct3 { field1: 0, field2: 0 }; //~ ERROR use of unstable library feature 'unstable_default'
    let _ = STRUCT3.field1; // ok
    let _: isize = STRUCT3.field1; // ok
    let _ = STRUCT3.field1 + 1; // ok
    // Note the aforementioned leak.
    let _: usize = STRUCT3.field2; // ok
    let _: Struct3<usize> = Struct3 { field1: 0, field2: 0 }; // ok
    let _ = STRUCT3.field2 + 1; // ok
    let _ = STRUCT3.field2 + 1usize; // ok
}