mirror of https://github.com/rust-lang/rust
47 lines
1.2 KiB
Rust
47 lines
1.2 KiB
Rust
// Tests that `as` casts from enums to numeric types succeed
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// only if the enum type is "unit-only" or "fieldless" as
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// described here: https://doc.rust-lang.org/reference/items/enumerations.html#casting
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pub enum UnitOnly {
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Foo,
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Bar,
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Baz,
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}
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pub enum Fieldless {
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Tuple(),
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Struct{},
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Unit,
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}
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pub enum NotUnitOnlyOrFieldless {
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Foo,
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Bar(u8),
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Baz
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}
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fn main() {
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let unit_only = UnitOnly::Foo;
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let _ = unit_only as isize;
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let _ = unit_only as i32;
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let _ = unit_only as usize;
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let _ = unit_only as u32;
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let fieldless = Fieldless::Struct{};
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let _ = fieldless as isize;
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let _ = fieldless as i32;
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let _ = fieldless as usize;
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let _ = fieldless as u32;
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let not_unit_only_or_fieldless = NotUnitOnlyOrFieldless::Foo;
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let _ = not_unit_only_or_fieldless as isize; //~ ERROR non-primitive cast: `NotUnitOnlyOrFieldless` as `isize`
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let _ = not_unit_only_or_fieldless as i32; //~ ERROR non-primitive cast: `NotUnitOnlyOrFieldless` as `i32`
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let _ = not_unit_only_or_fieldless as usize; //~ ERROR non-primitive cast: `NotUnitOnlyOrFieldless` as `usize`
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let _ = not_unit_only_or_fieldless as u32; //~ ERROR non-primitive cast: `NotUnitOnlyOrFieldless` as `u32`
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}
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