Relax constraint on NamespaceTag to be Clone/Copy.

src/lib.rs

@@ -56,12 +56,19 @@ pub trait NamespaceTag: 'static {
 }
 
 /// See crate documentation for general description.
-#[derive(Clone, Copy)]
 pub struct StoredString<Tag: 'static> {
     stored: &'static str,
     _ghost: std::marker::PhantomData<Tag>,
 }
 
+impl<Tag: 'static> Clone for StoredString<Tag> {
+    fn clone(&self) -> Self {
+        Self { stored: self.stored, _ghost: Default::default() }
+    }
+}
+
+impl<Tag: 'static> Copy for StoredString<Tag> { }
+
 impl<Tag: 'static> std::ops::Deref for StoredString<Tag> {
     type Target = str;
     fn deref(&self) -> &Self::Target {
@@ -211,13 +218,32 @@ impl<'l, Tag: 'static> From<&'l str> for StoredString<Tag> {
 
 #[cfg(test)]
 mod test_stored_string {
+    struct TestTag;
+
+    impl super::NamespaceTag for TestTag {
+        const PREFIX: &'static str = "test";
+    }
+
     impl super::NamespaceTag for () {
         const PREFIX: &'static str = "unit";
     }
 
     type SS = super::StoredString<()>;
+    type SST = super::StoredString<TestTag>;
     #[test]
     fn build_test() {
         assert_eq!(SS::new("ss"), SS::new("ss"));
+
+        assert_eq!(
+            SST::new("ss"),
+            SS::new("ss").coerce()
+        );
+
+        let ss = SST::new("ss");
+        let ss2 = ss.clone();
+        let ss3 = ss;
+
+        assert_eq!(ss, ss2);
+        assert_eq!(ss, ss3);
     }
 }