diff options
| -rw-r--r-- | src/librustc_mir/interpret/validity.rs | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/src/librustc_mir/interpret/validity.rs b/src/librustc_mir/interpret/validity.rs index 5192dfaa404..c64458bd989 100644 --- a/src/librustc_mir/interpret/validity.rs +++ b/src/librustc_mir/interpret/validity.rs @@ -50,11 +50,22 @@ macro_rules! try_validation { /// matched. Other errors are passed back to the caller, unchanged. This lets you use the patterns /// as a kind of validation blacklist: /// -/// ```rust -/// let v = try_validation_pat!(some_fn(), Foo | Bar | Baz, "some failure", path); +/// ``` +/// let v = try_validation_pat!(some_fn(), some_path, { +/// Foo | Bar | Baz => { "some failure" }, +/// }); /// // Failures that match $p are thrown up as validation errors, but other errors are passed back /// // unchanged. /// ``` +/// +/// An additional expected parameter can also be added to the failure message: +/// +/// ``` +/// let v = try_validation_pat!(some_fn(), some_path, { +/// Foo | Bar | Baz => { "some failure" } expected { "something that wasn't a failure" }, +/// }); +/// ``` +/// macro_rules! try_validation_pat { ($e:expr, $where:expr, { $( $p:pat )|* => { $what:tt } $( expected { $expected:expr } )? $( , )?}) => {{ match $e { |