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Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0533.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0533.md | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0533.md b/compiler/rustc_error_codes/src/error_codes/E0533.md new file mode 100644 index 000000000..279d728ca --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0533.md @@ -0,0 +1,34 @@ +An item which isn't a unit struct, a variant, nor a constant has been used as a +match pattern. + +Erroneous code example: + +```compile_fail,E0533 +struct Tortoise; + +impl Tortoise { + fn turtle(&self) -> u32 { 0 } +} + +match 0u32 { + Tortoise::turtle => {} // Error! + _ => {} +} +if let Tortoise::turtle = 0u32 {} // Same error! +``` + +If you want to match against a value returned by a method, you need to bind the +value first: + +``` +struct Tortoise; + +impl Tortoise { + fn turtle(&self) -> u32 { 0 } +} + +match 0u32 { + x if x == Tortoise.turtle() => {} // Bound into `x` then we compare it! + _ => {} +} +``` |