src/test/ui/associated-types/issue-82079.rs

   1 // check-pass
   2
   3 mod convenience_operators {
   4     use crate::{Op, Relation};
   5     use std::ops::AddAssign;
   6     use std::ops::Mul;
   7
   8     impl<C: Op> Relation<C> {
   9         pub fn map<F: Fn(C::D) -> D2 + 'static, D2: 'static>(
  10             self,
  11             f: F,
  12         ) -> Relation<impl Op<D = D2, R = C::R>> {
  13             self.map_dr(move |x, r| (f(x), r))
  14         }
  15     }
  16
  17     impl<K: 'static, V: 'static, C: Op<D = (K, V)>> Relation<C> {
  18         pub fn semijoin<C2: Op<D = K, R = R2>, R2, R3: AddAssign<R3>>(
  19             self,
  20             other: Relation<C2>,
  21         ) -> Relation<impl Op<D = C::D, R = R3>>
  22         where
  23             C::R: Mul<R2, Output = R3>,
  24         {
  25             self.join(other.map(|x| (x, ()))).map(|(k, x, ())| (k, x))
  26         }
  27     }
  28 }
  29
  30 mod core {
  31     mod operator {
  32         mod join {
  33             use super::Op;
  34             use crate::core::Relation;
  35             use std::ops::{AddAssign, Mul};
  36             struct Join<LC, RC> {
  37                 _left: LC,
  38                 _right: RC,
  39             }
  40             impl<
  41                     LC: Op<D = (K, LD), R = LR>,
  42                     RC: Op<D = (K, RD), R = RR>,
  43                     K: 'static,
  44                     LD: 'static,
  45                     LR: AddAssign<LR> + Mul<RR, Output = OR>,
  46                     RD: 'static,
  47                     RR: AddAssign<RR>,
  48                     OR: AddAssign<OR>,
  49                 > Op for Join<LC, RC>
  50             {
  51                 type D = (K, LD, RD);
  52                 type R = OR;
  53             }
  54             impl<K: 'static, D: 'static, C: Op<D = (K, D)>> Relation<C> {
  55                 pub fn join<C2: Op<D = (K, D2)>, D2: 'static, OR: AddAssign<OR>>(
  56                     self,
  57                     other: Relation<C2>,
  58                 ) -> Relation<impl Op<D = (K, D, D2), R = OR>>
  59                 where
  60                     C::R: Mul<C2::R, Output = OR>,
  61                 {
  62                     Relation {
  63                         inner: Join {
  64                             _left: self.inner,
  65                             _right: other.inner,
  66                         },
  67                     }
  68                 }
  69             }
  70         }
  71         mod map {
  72             use super::Op;
  73             use crate::core::Relation;
  74             use std::ops::AddAssign;
  75             struct Map<C, MF> {
  76                 _inner: C,
  77                 _op: MF,
  78             }
  79             impl<
  80                     D1,
  81                     R1,
  82                     D2: 'static,
  83                     R2: AddAssign<R2>,
  84                     C: Op<D = D1, R = R1>,
  85                     MF: Fn(D1, R1) -> (D2, R2),
  86                 > Op for Map<C, MF>
  87             {
  88                 type D = D2;
  89                 type R = R2;
  90             }
  91             impl<C: Op> Relation<C> {
  92                 pub fn map_dr<F: Fn(C::D, C::R) -> (D2, R2), D2: 'static, R2: AddAssign<R2>>(
  93                     self,
  94                     f: F,
  95                 ) -> Relation<impl Op<D = D2, R = R2>> {
  96                     Relation {
  97                         inner: Map {
  98                             _inner: self.inner,
  99                             _op: f,
 100                         },
 101                     }
 102                 }
 103             }
 104         }
 105         use std::ops::AddAssign;
 106         pub trait Op {
 107             type D: 'static;
 108             type R: AddAssign<Self::R>;
 109         }
 110     }
 111     pub use self::operator::Op;
 112     #[derive(Clone)]
 113     pub struct Relation<C> {
 114         inner: C,
 115     }
 116 }
 117
 118 use self::core::Op;
 119 pub use self::core::Relation;
 120
 121 fn main() {}