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rustc: Add long diagnostics for E0301

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Ruud van Asseldonk 2015-04-14 19:31:42 +02:00
parent 9c6f4b6d1d
commit ab1723b670
1 changed files with 14 additions and 1 deletions
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15
src/librustc/diagnostics.rs
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@ -139,6 +139,20 @@ for item in xs {
} }
"##, "##,
E0301: r##"
Mutable borrows are not allowed in pattern guards, because matching cannot have
side effects. Side effects could alter the matched object or the environment
on which the match depends in such a way, that the match would not be
exhaustive. For instance, the following would not match any arm if mutable
borrows were allowed:
match Some(()) {
None => { },
option if option.take().is_none() => { /* impossible, option is `Some` */ },
Some(_) => { } // When the previous match failed, the option became `None`.
}
"##,
E0303: r##" E0303: r##"
In certain cases it is possible for sub-bindings to violate memory safety. In certain cases it is possible for sub-bindings to violate memory safety.
Updates to the borrow checker in a future version of Rust may remove this Updates to the borrow checker in a future version of Rust may remove this
@ -224,7 +238,6 @@ register_diagnostics! {
E0298, // mismatched types between arms E0298, // mismatched types between arms
E0299, // mismatched types between arms E0299, // mismatched types between arms
E0300, // unexpanded macro E0300, // unexpanded macro
E0301, // cannot mutable borrow in a pattern guard
E0302, // cannot assign in a pattern guard E0302, // cannot assign in a pattern guard
E0304, // expected signed integer constant E0304, // expected signed integer constant
E0305, // expected constant E0305, // expected constant