mirror of https://github.com/rust-lang/rust.git
71 lines
1.6 KiB
Rust
71 lines
1.6 KiB
Rust
// Test that we have enough false edges to avoid exposing the exact matching
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// algorithm in borrow checking.
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#![feature(if_let_guard)]
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fn guard_always_precedes_arm(y: i32) {
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let mut x;
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// x should always be initialized, as the only way to reach the arm is
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// through the guard.
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match y {
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0 | 2 if { x = 2; true } => x,
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_ => 2,
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};
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let mut x;
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match y {
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0 | 2 if let Some(()) = { x = 2; Some(()) } => x,
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_ => 2,
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};
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}
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fn guard_may_be_skipped(y: i32) {
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let x;
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// Even though x *is* always initialized, we don't want to have borrowck
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// results be based on whether patterns are exhaustive.
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match y {
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_ if { x = 2; true } => 1,
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_ if {
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x; //~ ERROR E0381
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false
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} => 2,
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_ => 3,
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};
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let x;
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match y {
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_ if let Some(()) = { x = 2; Some(()) } => 1,
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_ if let Some(()) = {
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x; //~ ERROR E0381
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None
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} => 2,
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_ => 3,
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};
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}
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fn guard_may_be_taken(y: bool) {
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let x = String::new();
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// Even though x *is* never moved before the use, we don't want to have
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// borrowck results be based on whether patterns are disjoint.
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match y {
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false if { drop(x); true } => 1,
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true => {
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x; //~ ERROR use of moved value: `x`
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2
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}
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false => 3,
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};
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let x = String::new();
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match y {
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false if let Some(()) = { drop(x); Some(()) } => 1,
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true => {
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x; //~ ERROR use of moved value: `x`
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2
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}
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false => 3,
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};
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}
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fn main() {}
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