You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/mun/crates/mun_memory/src/type/ffi
    
    the code of the file until where you have to start completion: #![allow(dead_code)]

//! Defines an FFI compatible type interface for type information.

use std::{
    ffi::{c_void, CString},
    mem::ManuallyDrop,
    ops::Deref,
    os::raw::c_char,
    ptr,
    ptr::NonNull,
    sync::{atomic::Ordering, Arc},
};

use mun_abi::Guid;
use mun_capi_utils::{mun_error_try, try_deref_mut, ErrorHandle};
pub use r#array::ArrayInfo;
pub use r#pointer::PointerInfo;
pub use r#struct::{Field, Fields, StructInfo};

use crate::r#t
    
    fn test_mun_type_array_type_invalid_null() {
        let mut ffi_u64_array = MaybeUninit::uninit();
        assert_error_snapshot!(
            unsafe { mun_type_array_type(FFI_TYPE_NULL, ffi_u64_array.as_mut_ptr()) },
            @r###""invalid argument \'ty\': null pointer""###
        );

        let ffi_u64 = mun_type_primitive(PrimitiveType::U64);
        assert_error_snapshot!(
            unsafe { mun_type_array_type(ffi_u64, ptr::null_mut()) },
            @r###""invalid argument \'array_ty\': null pointer""###
        );
        unsafe { mun_type_release(ffi_u64) };
    }