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