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ddbf54b67d
This has now been approved as a language feature and no longer needs a `rustc_` prefix. Also change the `contracts` feature to be marked as incomplete and `contracts_internals` as internal.
27 lines
845 B
Rust
27 lines
845 B
Rust
//@ run-fail
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//@ compile-flags: -Zcontract-checks=yes
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#![feature(contracts)]
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//~^ WARN the feature `contracts` is incomplete and may not be safe to use and/or cause compiler crashes [incomplete_features]
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struct Baz {
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baz: i32
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}
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#[track_caller]
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#[core::contracts::requires(x.baz > 0)]
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#[core::contracts::ensures({let old = x.baz; move |ret:&Baz| ret.baz == old*2 })]
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// Relevant thing is this: ^^^^^^^^^^^^^^^
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// because we are capturing state that is Copy
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fn doubler(x: Baz) -> Baz {
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Baz { baz: x.baz + 10 }
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}
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fn main() {
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assert_eq!(doubler(Baz { baz: 10 }).baz, 20);
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assert_eq!(doubler(Baz { baz: 100 }).baz, 200);
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// This is a *run-fail* test because it is still exercising the
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// contract machinery, specifically because this second invocation
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// of `doubler` shows how the code does not meet its contract.
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}
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