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

Author: aldanor

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

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

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

@@ -4,4 +4,4 @@ error: proc-macro derive panicked
 4 | #[derive(H5Type)]
   |          ^^^^^^
   |
-  = help: message: H5Type requires #[repr(C)] or #[repr(packed)] for structs
+  = help: message: H5Type requires repr(C), repr(packed) or repr(transparent) for structs

hdf5-derive/tests/compile-fail/tuple-struct-no-repr.rs

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

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

@@ -4,4 +4,4 @@ error: proc-macro derive panicked
 4 | #[derive(H5Type)]
   |          ^^^^^^
   |
-  = help: message: H5Type requires #[repr(C)] or #[repr(packed)] for structs
+  = help: message: H5Type requires repr(C), repr(packed) or repr(transparent) for tuple structs

hdf5-derive/tests/test.rs

@@ -44,6 +44,16 @@ struct P1 {
 #[repr(packed)]
 struct P2(i8, u32);
 
+#[derive(H5Type)]
+#[repr(transparent)]
+struct T1 {
+    _x: u64,
+}
+
+#[derive(H5Type)]
+#[repr(transparent)]
+struct T2(i32);
+
 #[test]
 fn test_compound_packed() {
     assert_eq!(
@@ -68,6 +78,12 @@ fn test_compound_packed() {
     );
 }
 
+#[test]
+fn test_compound_transparent() {
+    assert_eq!(T1::type_descriptor(), u64::type_descriptor(),);
+    assert_eq!(T2::type_descriptor(), i32::type_descriptor(),);
+}
+
 #[test]
 fn test_compound_simple() {
     assert_eq!(