wayland: implement ext-foreign-toplevel-list-v1

src/utils/toplevel_identifier.rs

@@ -0,0 +1,28 @@
+use {
+    crate::utils::opaque::{opaque, Opaque, OpaqueError},
+    std::{
+        fmt::{Display, Formatter},
+        str::FromStr,
+    },
+};
+
+#[derive(Debug, Eq, PartialEq, Copy, Clone, Hash)]
+pub struct ToplevelIdentifier(Opaque);
+
+pub fn toplevel_identifier() -> ToplevelIdentifier {
+    ToplevelIdentifier(opaque())
+}
+
+impl Display for ToplevelIdentifier {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl FromStr for ToplevelIdentifier {
+    type Err = OpaqueError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Self(s.parse()?))
+    }
+}