47 lines
1.8 KiB
Rust
47 lines
1.8 KiB
Rust
fn with<T>(t: T, f: fn(T)) { f(t) }
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fn nested(x: &x/int) { // (1)
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do with(
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fn&(x: &x/int, // Refers to the region `x` at (1)
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y: &y/int, // A fresh region `y` (2)
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z: fn(x: &x/int, // Refers to `x` at (1)
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y: &y/int, // Refers to `y` at (2)
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z: &z/int) -> &z/int) // A fresh region `z` (3)
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-> &x/int {
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if false { return z(x, y, x); }
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if false { return z(x, y, y); }
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//~^ ERROR cannot infer an appropriate lifetime
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return z(y, x, x);
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//~^ ERROR mismatched types: expected `&x/int` but found `&y/int`
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//~^^ ERROR mismatched types: expected `&y/int` but found `&x/int`
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}
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) |foo| {
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let a: &x/int = foo(x, x, |_x, _y, z| z );
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let b: &x/int = foo(x, a, |_x, _y, z| z );
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let c: &x/int = foo(a, a, |_x, _y, z| z );
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let z = 3i;
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let d: &x/int = foo(x, x, |_x, _y, z| z );
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let e: &x/int = foo(x, &z, |_x, _y, z| z );
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// This would result in an error, but it is not reported by typeck
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// anymore but rather borrowck. Therefore, it doesn't end up
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// getting printed out since compilation fails after typeck.
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//
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// let f: &x/int = foo(&z, &z, |_x, _y, z| z ); // ERROR mismatched types: expected `&x/int` but found
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foo(x, &z, |x, _y, _z| x); //~ ERROR mismatched types: expected `&z/int` but found `&x/int`
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// Note: originally I had foo(x, &z, ...) here, but in that
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// case the region inferencer deduced that this was valid if
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// &y==&static, and so inference would succeed but borrow
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// check would fail because the lifetime of &z is not &static.
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foo(x, x, |_x, y, _z| y); //~ ERROR cannot infer an appropriate lifetime
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}
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}
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fn main() {} |