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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.
72 lines
2.1 KiB
Rust
72 lines
2.1 KiB
Rust
//! Test that contracts can be applied to generic functions.
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//@ revisions: unchk_pass chk_pass chk_fail_pre chk_fail_post chk_const_fail
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//
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//@ [unchk_pass] run-pass
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//@ [chk_pass] run-pass
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//
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//@ [chk_fail_pre] run-fail
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//@ [chk_fail_post] run-fail
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//@ [chk_const_fail] run-fail
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//
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//@ [unchk_pass] compile-flags: -Zcontract-checks=no
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//
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//@ [chk_pass] compile-flags: -Zcontract-checks=yes
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//@ [chk_fail_pre] compile-flags: -Zcontract-checks=yes
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//@ [chk_fail_post] compile-flags: -Zcontract-checks=yes
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//@ [chk_const_fail] 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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use std::ops::Sub;
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/// Dummy fn contract that precondition fails for val < 0, and post-condition fail for val == 1
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#[core::contracts::requires(val > 0u8.into())]
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#[core::contracts::ensures(|ret| *ret > 0u8.into())]
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fn decrement<T>(val: T) -> T
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where T: PartialOrd + Sub<Output=T> + From<u8>
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{
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val - 1u8.into()
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}
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/// Create a structure that takes a constant parameter.
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#[allow(dead_code)]
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struct Capped<const MAX: usize>(usize);
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/// Now declare a function to create stars which shouldn't exceed 5 stars.
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// Add redundant braces to ensure the built-in macro can handle this syntax.
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#[allow(unused_braces)]
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#[core::contracts::requires(num <= 5)]
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unsafe fn stars_unchecked(num: usize) -> Capped<{ 5 }> {
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Capped(num)
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}
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fn main() {
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check_decrement();
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check_stars();
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}
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fn check_stars() {
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// This should always pass.
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let _ = unsafe { stars_unchecked(3) };
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// This violates the contract.
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#[cfg(any(unchk_pass, chk_const_fail))]
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let _ = unsafe { stars_unchecked(10) };
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}
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fn check_decrement() {
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// This should always pass
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assert_eq!(decrement(10u8), 9u8);
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// This should fail requires but pass with no contract check.
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#[cfg(any(unchk_pass, chk_fail_pre))]
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assert_eq!(decrement(-2i128), -3i128);
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// This should fail ensures but pass with no contract check.
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#[cfg(any(unchk_pass, chk_fail_post))]
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assert_eq!(decrement(1i32), 0i32);
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}
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