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Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0665.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0665.md | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0665.md b/compiler/rustc_error_codes/src/error_codes/E0665.md new file mode 100644 index 000000000..ae54d6d15 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0665.md @@ -0,0 +1,33 @@ +#### Note: this error code is no longer emitted by the compiler. + +The `Default` trait was derived on an enum. + +Erroneous code example: + +```compile_fail +#[derive(Default)] +enum Food { + Sweet, + Salty, +} +``` + +The `Default` cannot be derived on an enum for the simple reason that the +compiler doesn't know which value to pick by default whereas it can for a +struct as long as all its fields implement the `Default` trait as well. + +If you still want to implement `Default` on your enum, you'll have to do it "by +hand": + +``` +enum Food { + Sweet, + Salty, +} + +impl Default for Food { + fn default() -> Food { + Food::Sweet + } +} +``` |