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Diffstat (limited to 'compiler/rustc_error_codes/src/error_codes/E0755.md')
-rw-r--r-- | compiler/rustc_error_codes/src/error_codes/E0755.md | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/compiler/rustc_error_codes/src/error_codes/E0755.md b/compiler/rustc_error_codes/src/error_codes/E0755.md new file mode 100644 index 000000000..88b7f4849 --- /dev/null +++ b/compiler/rustc_error_codes/src/error_codes/E0755.md @@ -0,0 +1,28 @@ +The `ffi_pure` attribute was used on a non-foreign function. + +Erroneous code example: + +```compile_fail,E0755 +#![feature(ffi_pure)] + +#[ffi_pure] // error! +pub fn foo() {} +# fn main() {} +``` + +The `ffi_pure` attribute can only be used on foreign functions which do not have +side effects or infinite loops: + +``` +#![feature(ffi_pure)] + +extern "C" { + #[ffi_pure] // ok! + pub fn strlen(s: *const i8) -> isize; +} +# fn main() {} +``` + +You can find more information about it in the [unstable Rust Book]. + +[unstable Rust Book]: https://doc.rust-lang.org/unstable-book/language-features/ffi-pure.html |