A unrecognized representation attribute was used.
Erroneous code example:
#[repr(D)] // error: unrecognized representation hint struct MyStruct { my_field: usize }
You can use a repr
attribute to tell the compiler how you want a struct or enum to be laid out in memory.
Make sure you're using one of the supported options:
#[repr(C)] // ok! struct MyStruct { my_field: usize }
For more information about specifying representations, see the “Alternative Representations” section of the Rustonomicon.