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Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0367.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0367.md | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0367.md b/compiler/rustc_error_codes/src/error_codes/E0367.md new file mode 100644 index 000000000..cfebeada2 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0367.md @@ -0,0 +1,36 @@ +An attempt was made to implement `Drop` on a specialization of a generic type. + +Erroneous code example: + +```compile_fail,E0367 +trait Foo {} + +struct MyStruct<T> { + t: T +} + +impl<T: Foo> Drop for MyStruct<T> { + fn drop(&mut self) {} +} +``` + +This code is not legal: it is not possible to specialize `Drop` to a subset of +implementations of a generic type. In order for this code to work, `MyStruct` +must also require that `T` implements `Foo`. Alternatively, another option is +to wrap the generic type in another that specializes appropriately: + +``` +trait Foo{} + +struct MyStruct<T> { + t: T +} + +struct MyStructWrapper<T: Foo> { + t: MyStruct<T> +} + +impl <T: Foo> Drop for MyStructWrapper<T> { + fn drop(&mut self) {} +} +``` |