"error: generic param redefined multiple times" when trying to use the same generic param multiple times in the same extern block

[bjorn3]

I tried this code:

extern "rust-intrinsic" {
    fn size_of<T>() -> usize;
    fn transmute<T, U>(_: T) -> U;
}

I expected to see this happen: It compiles

Instead, this happened:

<source>:3:18: error: generic param redefined multiple times
    3 |     fn transmute<T, U>(_: T) -> U;
      |                  ^
<source>:2:16: error: was defined here
    2 |     fn size_of<T>() -> usize;
      |                ^
Compiler returned: 1

Meta

• What version of Rust GCC were you using, git sha if possible.

[philberty]

We haven't implemented transmute yet so we could use the offset intrinsic instead which causes the same issue.

extern "rust-intrinsic" {
    fn size_of<T>() -> usize;
    fn offset<T>(dst: *const T, offset: isize) -> *const T;
}