mismatched types between c_void and boxed closure

[izgzhen]

When compiled with nightly rustc, this line will report error:

src/asymmetric.rs:271:57: 271:74 error: mismatched types:
 expected `*mut libc::types::common::c95::c_void`,
    found `Box<[closure@src/asymmetric.rs:220:23: 269:10 puller_ref:_, f:_, coro_ref:_]>`
(expected *-ptr,
    found box) [E0308]    
src/asymmetric.rs:271         coro.context.init_with(coroutine_initialize, 0, Box::new(wrapper), &mut stack);

I searched a bit and find a solution from this post: change Box::new(wrapper) into &wrapper as *const _ as *mut libc::c_void

It compiled. But honestly, I am not very familiar with low-level rust so I have no idea why the Box::new is wrong and this casting is right.

[izgzhen]

Oh, this is still not working. I got bus error when trying to run examples/simple.rs

[zonyitoo]

No, you can't. You should use Box::into_raw(wrapper) as *const _ as *mut libc::c_void

[izgzhen]

Not working, it doesn't typecheck :(

src/asymmetric.rs:271:71: 271:78 error: mismatched types:
 expected `Box<_>`,
    found `[closure@src/asymmetric.rs:220:23: 269:10 puller_ref:_, f:_, coro_ref:_]`
(expected box,
    found closure) [E0308]
src/asymmetric.rs:271         coro.context.init_with(coroutine_initialize, 0, Box::into_raw(wrapper) as *const _ as *mut libc::c_void, &mut stack);

Or if I first box it then Box::into_raw, it will still lead to runtime error

[zonyitoo]

Please refer to this one: https://github.com/zonyitoo/context-rs/blob/master/examples/asymmetric.rs

They should be almost the same. I am extremely busy these days so I am not going to fix this lately.