117 lines
2.6 KiB
Rust
117 lines
2.6 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![allow(unknown_features)]
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#![feature(box_syntax)]
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struct Fat<T: ?Sized> {
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f1: isize,
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f2: &'static str,
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ptr: T
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}
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#[derive(Copy, Clone, PartialEq, Eq, Debug)]
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struct Bar;
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#[derive(Copy, Clone, PartialEq, Eq)]
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struct Bar1 {
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f: isize
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}
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trait ToBar {
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fn to_bar(&self) -> Bar;
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fn to_val(&self) -> isize;
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}
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impl ToBar for Bar {
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fn to_bar(&self) -> Bar {
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*self
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}
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fn to_val(&self) -> isize {
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0
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}
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}
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impl ToBar for Bar1 {
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fn to_bar(&self) -> Bar {
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Bar
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}
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fn to_val(&self) -> isize {
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self.f
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}
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}
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// x is a fat pointer
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fn foo(x: &Fat<ToBar>) {
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assert_eq!(x.f1, 5);
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assert_eq!(x.f2, "some str");
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assert_eq!(x.ptr.to_bar(), Bar);
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assert_eq!(x.ptr.to_val(), 42);
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let y = &x.ptr;
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assert_eq!(y.to_bar(), Bar);
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assert_eq!(y.to_val(), 42);
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}
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fn bar(x: &ToBar) {
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assert_eq!(x.to_bar(), Bar);
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assert_eq!(x.to_val(), 42);
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}
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fn baz(x: &Fat<Fat<ToBar>>) {
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assert_eq!(x.f1, 5);
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assert_eq!(x.f2, "some str");
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assert_eq!(x.ptr.f1, 8);
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assert_eq!(x.ptr.f2, "deep str");
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assert_eq!(x.ptr.ptr.to_bar(), Bar);
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assert_eq!(x.ptr.ptr.to_val(), 42);
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let y = &x.ptr.ptr;
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assert_eq!(y.to_bar(), Bar);
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assert_eq!(y.to_val(), 42);
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}
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pub fn main() {
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let f1 = Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
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foo(&f1);
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let f2 = &f1;
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foo(f2);
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let f3: &Fat<ToBar> = f2;
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foo(f3);
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let f4: &Fat<ToBar> = &f1;
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foo(f4);
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let f5: &Fat<ToBar> = &Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
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foo(f5);
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// Zero size object.
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let f6: &Fat<ToBar> = &Fat { f1: 5, f2: "some str", ptr: Bar };
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assert_eq!(f6.ptr.to_bar(), Bar);
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// &*
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//
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let f7: Box<ToBar> = Box::new(Bar1 {f :42});
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bar(&*f7);
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// Deep nesting
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let f1 =
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Fat { f1: 5, f2: "some str", ptr: Fat { f1: 8, f2: "deep str", ptr: Bar1 {f :42}} };
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baz(&f1);
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let f2 = &f1;
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baz(f2);
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let f3: &Fat<Fat<ToBar>> = f2;
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baz(f3);
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let f4: &Fat<Fat<ToBar>> = &f1;
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baz(f4);
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let f5: &Fat<Fat<ToBar>> =
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&Fat { f1: 5, f2: "some str", ptr: Fat { f1: 8, f2: "deep str", ptr: Bar1 {f :42}} };
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baz(f5);
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}
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