56 lines
1.1 KiB
Rust
56 lines
1.1 KiB
Rust
struct Point {
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x: int,
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y: int,
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}
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impl Point : ops::Add<int,int> {
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pure fn add(&self, z: &int) -> int {
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self.x + self.y + (*z)
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}
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}
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impl Point {
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fn times(z: int) -> int {
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self.x * self.y * z
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}
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}
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fn a() {
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let mut p = Point {x: 3, y: 4};
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// ok (we can loan out rcvr)
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p + 3;
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p.times(3);
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}
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fn b() {
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let mut p = Point {x: 3, y: 4};
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// Here I create an outstanding loan and check that we get conflicts:
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let q = &mut p; //~ NOTE prior loan as mutable granted here
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p + 3; //~ ERROR loan of mutable local variable as immutable conflicts with prior loan
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p.times(3); //~ ERROR loan of mutable local variable as immutable conflicts with prior loan
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q.x += 1;
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}
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fn c() {
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// Here the receiver is in aliased memory and hence we cannot
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// consider it immutable:
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let q = @mut Point {x: 3, y: 4};
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// ...this is ok for pure fns
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*q + 3;
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// ...but not impure fns
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(*q).times(3); //~ ERROR illegal borrow unless pure
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//~^ NOTE impure due to access to impure function
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}
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fn main() {
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}
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