diff options
| -rw-r--r-- | src/librustc_error_codes/error_codes/E0617.md | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/librustc_error_codes/error_codes/E0617.md b/src/librustc_error_codes/error_codes/E0617.md index f4357ff755e..61b56766c26 100644 --- a/src/librustc_error_codes/error_codes/E0617.md +++ b/src/librustc_error_codes/error_codes/E0617.md @@ -17,3 +17,14 @@ Certain Rust types must be cast before passing them to a variadic function, because of arcane ABI rules dictated by the C standard. To fix the error, cast the value to the type specified by the error message (which you may need to import from `std::os::raw`). + +In this case, `c_double` has the same size as `f64` so we can use it directly: + +```no_run +# extern { +# fn printf(c: *const i8, ...); +# } +unsafe { + printf(::std::ptr::null(), 0f64); // ok! +} +``` |