Vendor things

third-party/vendor/objc2-encode/examples/ns_uinteger.rs

@@ -0,0 +1,32 @@
+//! Implementing `Encode` and `RefEncode` for `NSUInteger`.
+//!
+//! Note that in this case `NSUInteger` could actually just be a type alias
+//! for `usize`, and that's already available under `objc2::ffi::NSUInteger`.
+use objc2_encode::{Encode, Encoding, RefEncode};
+
+#[repr(transparent)]
+struct NSUInteger {
+    _inner: usize,
+}
+
+// SAFETY: `NSUInteger` has the same `repr` as `usize`.
+unsafe impl Encode for NSUInteger {
+    /// Running `@encode(NSUInteger)` gives `Q` on 64-bit systems and `I` on
+    /// 32-bit systems. This corresponds exactly to `usize`, which is also how
+    /// we've defined our struct.
+    const ENCODING: Encoding = usize::ENCODING;
+}
+
+// SAFETY: `&NSUInteger` has the same representation as `&usize`.
+unsafe impl RefEncode for NSUInteger {
+    /// Running `@encode(NSUInteger*)` gives `^Q` on 64-bit systems and `^I`
+    /// on 32-bit systems. So implementing `RefEncode` as a plain pointer is
+    /// correct.
+    const ENCODING_REF: Encoding = Encoding::Pointer(&NSUInteger::ENCODING);
+}
+
+fn main() {
+    assert!(NSUInteger::ENCODING.equivalent_to_str("Q"));
+    assert!(<&NSUInteger>::ENCODING.equivalent_to_str("^Q"));
+    assert!(<&NSUInteger>::ENCODING.equivalent_to_str("r^Q"));
+}