48 lines
981 B
Rust
48 lines
981 B
Rust
#![deny(unused_must_use)]
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#[must_use]
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struct S;
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struct A;
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#[must_use]
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trait T {}
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impl T for A {}
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fn empty() -> [S; 0] {
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[]
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}
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fn singleton() -> [S; 1] {
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[S]
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}
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fn many() -> [S; 4] {
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[S, S, S, S]
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}
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fn array_of_impl_trait() -> [impl T; 2] {
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[A, A]
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}
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fn impl_array() -> [(u8, Box<dyn T>); 2] {
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[(0, Box::new(A)), (0, Box::new(A))]
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}
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fn array_of_arrays_of_arrays() -> [[[S; 1]; 2]; 1] {
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[[[S], [S]]]
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}
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fn main() {
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empty(); // ok
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singleton(); //~ ERROR unused array of `S` that must be used
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many(); //~ ERROR unused array of `S` that must be used
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([S], 0, ()); //~ ERROR unused array of `S` in tuple element 0 that must be used
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array_of_impl_trait(); //~ ERROR unused array of implementers of `T` that must be used
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impl_array();
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//~^ ERROR unused array of boxed `T` trait objects in tuple element 1 that must be used
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array_of_arrays_of_arrays();
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//~^ ERROR unused array of arrays of arrays of `S` that must be used
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}
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