Function callback_ret_buffer 

pub unsafe fn callback_ret_buffer<T: BufferValue>(
    ptr: *mut u8,
    len: usize,
) -> Result<T, ForeignError>

Adopt and decode a value buffer a vtable entry wrote to its out_ptr/out_len slots.

Errors

Returns a MARSHAL_ERROR_CODE failure for a null pointer with a non-zero length or a malformed buffer.

Safety

Same contract as callback_ret_bytes, and every object token in the buffer must carry an unadopted reference (see BufferValue::read_value).