mirror of https://github.com/rust-lang/rust
42 lines
818 B
Rust
42 lines
818 B
Rust
// Forbid assignment into a dynamically sized type.
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struct Fat<T: ?Sized> {
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f1: isize,
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f2: &'static str,
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ptr: T
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}
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#[derive(PartialEq,Eq)]
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struct Bar;
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#[derive(PartialEq,Eq)]
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struct Bar1 {
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f: isize
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}
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trait ToBar {
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fn to_bar(&self) -> Bar;
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fn to_val(&self) -> isize;
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}
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impl ToBar for Bar1 {
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fn to_bar(&self) -> Bar {
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Bar
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}
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fn to_val(&self) -> isize {
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self.f
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}
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}
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pub fn main() {
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// Assignment.
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let f5: &mut Fat<dyn ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
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let z: Box<dyn ToBar> = Box::new(Bar1 {f: 36});
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f5.ptr = Bar1 {f: 36};
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//~^ ERROR mismatched types
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//~| expected `dyn ToBar`, found `Bar1`
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//~| expected trait object `dyn ToBar`
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//~| found struct `Bar1`
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//~| ERROR the size for values of type
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}
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