Update hdf5-derive tests re: #[repr(packed)

Author: aldanor

hdf5-derive/tests/compile-fail/struct-c-repr.stderr

@@ -3,7 +3,7 @@ use hdf5_derive::H5Type;
 
 #[derive(H5Type)]
 //~^ ERROR proc-macro derive
-//~^^ HELP H5Type requires #[repr(C)] for structs
+//~^^ HELP H5Type requires #[repr(C)] or #[repr(packed)] for structs
 struct Foo {
     bar: i64,
 }

…rive/tests/compile-fail/struct-c-repr.rs …ive/tests/compile-fail/struct-no-repr.rshdf5-derive/tests/compile-fail/struct-c-repr.rs renamed to hdf5-derive/tests/compile-fail/struct-no-repr.rs hdf5-derive/tests/compile-fail/struct-c-repr.rs renamed to hdf5-derive/tests/compile-fail/struct-no-repr.rs

@@ -0,0 +1,7 @@
+error: proc-macro derive panicked
+ --> $DIR/struct-no-repr.rs:4:10
+  |
+4 | #[derive(H5Type)]
+  |          ^^^^^^
+  |
+  = help: message: H5Type requires #[repr(C)] or #[repr(packed)] for structs

hdf5-derive/tests/compile-fail/struct-no-repr.stderr

@@ -3,7 +3,7 @@ use hdf5_derive::H5Type;
 
 #[derive(H5Type)]
 //~^ ERROR proc-macro derive
-//~^^ HELP H5Type requires #[repr(C)] for structs
+//~^^ HELP H5Type requires #[repr(C)] or #[repr(packed)] for structs
 struct Foo(i64);
 
 fn main() {}

hdf5-derive/tests/compile-fail/tuple-struct-c-repr.stderr

@@ -0,0 +1,7 @@
+error: proc-macro derive panicked
+ --> $DIR/tuple-struct-no-repr.rs:4:10
+  |
+4 | #[derive(H5Type)]
+  |          ^^^^^^
+  |
+  = help: message: H5Type requires #[repr(C)] or #[repr(packed)] for structs

…ests/compile-fail/tuple-struct-c-repr.rs …sts/compile-fail/tuple-struct-no-repr.rshdf5-derive/tests/compile-fail/tuple-struct-c-repr.rs renamed to hdf5-derive/tests/compile-fail/tuple-struct-no-repr.rs hdf5-derive/tests/compile-fail/tuple-struct-c-repr.rs renamed to hdf5-derive/tests/compile-fail/tuple-struct-no-repr.rs

@@ -1,3 +1,6 @@
+// due to compiler wrongfully complaining re: Copy impl missing for packed struct
+#![allow(unaligned_references)]
+
 #[macro_use]
 extern crate hdf5_derive;
 
@@ -30,6 +33,41 @@ struct B {
 #[repr(C)]
 struct T(i64, pub u64);
 
+#[derive(H5Type, Copy, Clone)]
+#[repr(packed)]
+struct P1 {
+    x: u8,
+    y: u64,
+}
+
+#[derive(H5Type, Copy, Clone)]
+#[repr(packed)]
+struct P2(i8, u32);
+
+#[test]
+fn test_compound_packed() {
+    assert_eq!(
+        P1::type_descriptor(),
+        TD::Compound(CompoundType {
+            fields: vec![
+                CompoundField::typed::<u8>("x", 0, 0),
+                CompoundField::typed::<u64>("y", 1, 1),
+            ],
+            size: 9,
+        })
+    );
+    assert_eq!(
+        P2::type_descriptor(),
+        TD::Compound(CompoundType {
+            fields: vec![
+                CompoundField::typed::<i8>("0", 0, 0),
+                CompoundField::typed::<u32>("1", 1, 1),
+            ],
+            size: 5,
+        })
+    );
+}
+
 #[test]
 fn test_compound_simple() {
     assert_eq!(