src/test/ui/polymorphization/generators.rs

   1 // build-fail
   2 // compile-flags:-Zpolymorphize=on -Zinline-mir=off
   3 #![feature(generic_const_exprs, generators, generator_trait, rustc_attrs)]
   4 //~^ WARN the feature `generic_const_exprs` is incomplete
   5
   6 use std::marker::Unpin;
   7 use std::ops::{Generator, GeneratorState};
   8 use std::pin::Pin;
   9
  10 enum YieldOrReturn<Y, R> {
  11     Yield(Y),
  12     Return(R),
  13 }
  14
  15 fn finish<T, Y, R>(mut t: T) -> Vec<YieldOrReturn<Y, R>>
  16 where
  17     T: Generator<(), Yield = Y, Return = R> + Unpin,
  18 {
  19     let mut results = Vec::new();
  20     loop {
  21         match Pin::new(&mut t).resume(()) {
  22             GeneratorState::Yielded(yielded) => results.push(YieldOrReturn::Yield(yielded)),
  23             GeneratorState::Complete(returned) => {
  24                 results.push(YieldOrReturn::Return(returned));
  25                 return results;
  26             }
  27         }
  28     }
  29 }
  30
  31 // This test checks that the polymorphization analysis functions on generators.
  32
  33 #[rustc_polymorphize_error]
  34 pub fn unused_type<T>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
  35     || {
  36         //~^ ERROR item has unused generic parameters
  37         yield 1;
  38         2
  39     }
  40 }
  41
  42 #[rustc_polymorphize_error]
  43 pub fn used_type_in_yield<Y: Default>() -> impl Generator<(), Yield = Y, Return = u32> + Unpin {
  44     || {
  45         yield Y::default();
  46         2
  47     }
  48 }
  49
  50 #[rustc_polymorphize_error]
  51 pub fn used_type_in_return<R: Default>() -> impl Generator<(), Yield = u32, Return = R> + Unpin {
  52     || {
  53         yield 3;
  54         R::default()
  55     }
  56 }
  57
  58 #[rustc_polymorphize_error]
  59 pub fn unused_const<const T: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin {
  60     || {
  61         //~^ ERROR item has unused generic parameters
  62         yield 1;
  63         2
  64     }
  65 }
  66
  67 #[rustc_polymorphize_error]
  68 pub fn used_const_in_yield<const Y: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin
  69 {
  70     || {
  71         yield Y;
  72         2
  73     }
  74 }
  75
  76 #[rustc_polymorphize_error]
  77 pub fn used_const_in_return<const R: u32>() -> impl Generator<(), Yield = u32, Return = u32> + Unpin
  78 {
  79     || {
  80         yield 4;
  81         R
  82     }
  83 }
  84
  85 fn main() {
  86     finish(unused_type::<u32>());
  87     finish(used_type_in_yield::<u32>());
  88     finish(used_type_in_return::<u32>());
  89     finish(unused_const::<1u32>());
  90     finish(used_const_in_yield::<1u32>());
  91     finish(used_const_in_return::<1u32>());
  92 }