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Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0711.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0711.md | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0711.md b/compiler/rustc_error_codes/src/error_codes/E0711.md new file mode 100644 index 000000000..a2150037f --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0711.md @@ -0,0 +1,30 @@ +#### This error code is internal to the compiler and will not be emitted with normal Rust code. + +Feature declared with conflicting stability requirements. + +```compile_fail,E0711 +// NOTE: this attribute is perma-unstable and should *never* be used outside of +// stdlib and the compiler. +#![feature(staged_api)] + +#![stable(feature = "...", since = "1.0.0")] + +#[stable(feature = "foo", since = "1.0.0")] +fn foo_stable_1_0_0() {} + +// error: feature `foo` is declared stable since 1.29.0 +#[stable(feature = "foo", since = "1.29.0")] +fn foo_stable_1_29_0() {} + +// error: feature `foo` is declared unstable +#[unstable(feature = "foo", issue = "none")] +fn foo_unstable() {} +``` + +In the above example, the `foo` feature is first defined to be stable since +1.0.0, but is then re-declared stable since 1.29.0. This discrepancy in +versions causes an error. Furthermore, `foo` is then re-declared as unstable, +again the conflict causes an error. + +This error can be fixed by splitting the feature, this allows any +stability requirements and removes any possibility of conflict. |