summaryrefslogtreecommitdiffstats
path: root/src/test/ui/closures/issue-72408-nested-closures-exponential.rs
blob: 2d6ba936572d58385393c043f808eb67f4958c6d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
// build-pass

// Closures include captured types twice in a type tree.
//
// Wrapping one closure with another leads to doubling
// the amount of types in the type tree.
//
// This test ensures that rust can handle
// deeply nested type trees with a lot
// of duplicated subtrees.

fn dup(f: impl Fn(i32) -> i32) -> impl Fn(i32) -> i32 {
    move |a| f(a * 2)
}

fn main() {
    let f = |a| a;

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    // Compiler dies around here if it tries
    // to walk the tree exhaustively.

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);
    let f = dup(f);

    println!("Type size was at least {}", f(1));
}