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| 1 | +// See drop-order-comparisons.rs |
| 2 | + |
| 3 | +//@ edition: 2024 |
| 4 | +//@ run-pass |
| 5 | + |
| 6 | +#![feature(if_let_guard)] |
| 7 | + |
| 8 | +fn t_if_let_chains_then() { |
| 9 | + let e = Events::new(); |
| 10 | + _ = if e.ok(1).is_ok() |
| 11 | + && let true = e.ok(9).is_ok() |
| 12 | + && let Ok(_v) = e.ok(8) |
| 13 | + && let Ok(_) = e.ok(7) |
| 14 | + && let Ok(_) = e.ok(6).as_ref() |
| 15 | + && e.ok(2).is_ok() |
| 16 | + && let Ok(_v) = e.ok(5) |
| 17 | + && let Ok(_) = e.ok(4).as_ref() { |
| 18 | + e.mark(3); |
| 19 | + }; |
| 20 | + e.assert(9); |
| 21 | +} |
| 22 | + |
| 23 | +fn t_guard_if_let_chains_then() { |
| 24 | + let e = Events::new(); |
| 25 | + _ = match () { |
| 26 | + () if e.ok(1).is_ok() |
| 27 | + && let true = e.ok(9).is_ok() |
| 28 | + && let Ok(_v) = e.ok(8) |
| 29 | + && let Ok(_) = e.ok(7) |
| 30 | + && let Ok(_) = e.ok(6).as_ref() |
| 31 | + && e.ok(2).is_ok() |
| 32 | + && let Ok(_v) = e.ok(5) |
| 33 | + && let Ok(_) = e.ok(4).as_ref() => { |
| 34 | + e.mark(3); |
| 35 | + } |
| 36 | + _ => {} |
| 37 | + }; |
| 38 | + e.assert(9); |
| 39 | +} |
| 40 | + |
| 41 | +fn t_if_let_chains_then_else() { |
| 42 | + let e = Events::new(); |
| 43 | + _ = if e.ok(1).is_ok() |
| 44 | + && let true = e.ok(8).is_ok() |
| 45 | + && let Ok(_v) = e.ok(7) |
| 46 | + && let Ok(_) = e.ok(6) |
| 47 | + && let Ok(_) = e.ok(5).as_ref() |
| 48 | + && e.ok(2).is_ok() |
| 49 | + && let Ok(_v) = e.ok(4) |
| 50 | + && let Ok(_) = e.err(3) {} else { |
| 51 | + e.mark(9); |
| 52 | + }; |
| 53 | + e.assert(9); |
| 54 | +} |
| 55 | + |
| 56 | +fn t_guard_if_let_chains_then_else() { |
| 57 | + let e = Events::new(); |
| 58 | + _ = match () { |
| 59 | + () if e.ok(1).is_ok() |
| 60 | + && let true = e.ok(8).is_ok() |
| 61 | + && let Ok(_v) = e.ok(7) |
| 62 | + && let Ok(_) = e.ok(6) |
| 63 | + && let Ok(_) = e.ok(5).as_ref() |
| 64 | + && e.ok(2).is_ok() |
| 65 | + && let Ok(_v) = e.ok(4) |
| 66 | + && let Ok(_) = e.err(3) => {} |
| 67 | + _ => { |
| 68 | + e.mark(9); |
| 69 | + } |
| 70 | + }; |
| 71 | + e.assert(9); |
| 72 | +} |
| 73 | + |
| 74 | +fn main() { |
| 75 | + t_if_let_chains_then(); |
| 76 | + t_guard_if_let_chains_then(); |
| 77 | + t_if_let_chains_then_else(); |
| 78 | + t_guard_if_let_chains_then_else(); |
| 79 | +} |
| 80 | + |
| 81 | +// # Test scaffolding |
| 82 | + |
| 83 | +use core::cell::RefCell; |
| 84 | +use std::collections::HashSet; |
| 85 | + |
| 86 | +/// A buffer to track the order of events. |
| 87 | +/// |
| 88 | +/// First, numbered events are logged into this buffer. |
| 89 | +/// |
| 90 | +/// Then, `assert` is called to verify that the correct number of |
| 91 | +/// events were logged, and that they were logged in the expected |
| 92 | +/// order. |
| 93 | +struct Events(RefCell<Option<Vec<u64>>>); |
| 94 | + |
| 95 | +impl Events { |
| 96 | + const fn new() -> Self { |
| 97 | + Self(RefCell::new(Some(Vec::new()))) |
| 98 | + } |
| 99 | + #[track_caller] |
| 100 | + fn assert(&self, max: u64) { |
| 101 | + let buf = &self.0; |
| 102 | + let v1 = buf.borrow().as_ref().unwrap().clone(); |
| 103 | + let mut v2 = buf.borrow().as_ref().unwrap().clone(); |
| 104 | + *buf.borrow_mut() = None; |
| 105 | + v2.sort(); |
| 106 | + let uniq_len = v2.iter().collect::<HashSet<_>>().len(); |
| 107 | + // Check that the sequence is sorted. |
| 108 | + assert_eq!(v1, v2); |
| 109 | + // Check that there are no duplicates. |
| 110 | + assert_eq!(v2.len(), uniq_len); |
| 111 | + // Check that the length is the expected one. |
| 112 | + assert_eq!(max, uniq_len as u64); |
| 113 | + // Check that the last marker is the expected one. |
| 114 | + assert_eq!(v2.last().unwrap(), &max); |
| 115 | + } |
| 116 | + /// Return an `Ok` value that logs its drop. |
| 117 | + fn ok(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> { |
| 118 | + Ok(LogDrop(self, m)) |
| 119 | + } |
| 120 | + /// Return an `Err` value that logs its drop. |
| 121 | + fn err(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> { |
| 122 | + Err(LogDrop(self, m)) |
| 123 | + } |
| 124 | + /// Log an event. |
| 125 | + fn mark(&self, m: u64) { |
| 126 | + self.0.borrow_mut().as_mut().unwrap().push(m); |
| 127 | + } |
| 128 | +} |
| 129 | + |
| 130 | +impl Drop for Events { |
| 131 | + fn drop(&mut self) { |
| 132 | + if self.0.borrow().is_some() { |
| 133 | + panic!("failed to call `Events::assert()`"); |
| 134 | + } |
| 135 | + } |
| 136 | +} |
| 137 | + |
| 138 | +/// A type that logs its drop events. |
| 139 | +struct LogDrop<'b>(&'b Events, u64); |
| 140 | + |
| 141 | +impl<'b> Drop for LogDrop<'b> { |
| 142 | + fn drop(&mut self) { |
| 143 | + self.0.mark(self.1); |
| 144 | + } |
| 145 | +} |
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