rustc: Add long diagnostics for E0162

This commit is contained in:
Ruud van Asseldonk 2015-04-14 20:00:17 +02:00
parent 48a376da18
commit c45eacdbc6

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@ -112,6 +112,25 @@ reference when using guards or refactor the entire expression, perhaps by
putting the condition inside the body of the arm.
"##,
E0162: r##"
An if-let pattern attempts to match the pattern, and enters the body if the
match was succesful. If the match is irrefutable (when it cannot fail to match),
use a regular `let`-binding instead. For instance:
struct Irrefutable(i32);
let irr = Irrefutable(0);
// This fails to compile because the match is irrefutable.
if let Irrefutable(x) = irr {
// This body will always be executed.
foo(x);
}
// Try this instead:
let Irrefutable(x) = irr;
foo(x);
"##,
E0297: r##"
Patterns used to bind names must be irrefutable. That is, they must guarantee
that a name will be extracted in all cases. Instead of pattern matching the
@ -220,7 +239,6 @@ register_diagnostics! {
E0152,
E0158,
E0161,
E0162,
E0165,
E0170,
E0261, // use of undeclared lifetime name