#![allow(unused)] use std::cmp::Eq; use std::collections::{HashMap, HashSet}; use std::hash::{BuildHasher, Hash}; pub trait Foo<T>: Sized { fn make() -> (Self, Self); } impl<K: Hash + Eq, V> Foo<i8> for HashMap<K, V> { fn make() -> (Self, Self) { // OK, don't suggest to modify these let _: HashMap<i32, i32> = HashMap::new(); let _: HashSet<i32> = HashSet::new(); (HashMap::new(), HashMap::with_capacity(10)) } } impl<K: Hash + Eq, V> Foo<i8> for (HashMap<K, V>,) { fn make() -> (Self, Self) { ((HashMap::new(),), (HashMap::with_capacity(10),)) } } impl Foo<i16> for HashMap<String, String> { fn make() -> (Self, Self) { (HashMap::new(), HashMap::with_capacity(10)) } } impl<K: Hash + Eq, V, S: BuildHasher + Default> Foo<i32> for HashMap<K, V, S> { fn make() -> (Self, Self) { (HashMap::default(), HashMap::with_capacity_and_hasher(10, S::default())) } } impl<S: BuildHasher + Default> Foo<i64> for HashMap<String, String, S> { fn make() -> (Self, Self) { (HashMap::default(), HashMap::with_capacity_and_hasher(10, S::default())) } } impl<T: Hash + Eq> Foo<i8> for HashSet<T> { fn make() -> (Self, Self) { (HashSet::new(), HashSet::with_capacity(10)) } } impl Foo<i16> for HashSet<String> { fn make() -> (Self, Self) { (HashSet::new(), HashSet::with_capacity(10)) } } impl<T: Hash + Eq, S: BuildHasher + Default> Foo<i32> for HashSet<T, S> { fn make() -> (Self, Self) { (HashSet::default(), HashSet::with_capacity_and_hasher(10, S::default())) } } impl<S: BuildHasher + Default> Foo<i64> for HashSet<String, S> { fn make() -> (Self, Self) { (HashSet::default(), HashSet::with_capacity_and_hasher(10, S::default())) } } pub fn foo(_map: &mut HashMap<i32, i32>, _set: &mut HashSet<i32>) {} macro_rules! gen { (impl) => { impl<K: Hash + Eq, V> Foo<u8> for HashMap<K, V> { fn make() -> (Self, Self) { (HashMap::new(), HashMap::with_capacity(10)) } } }; (fn $name:ident) => { pub fn $name(_map: &mut HashMap<i32, i32>, _set: &mut HashSet<i32>) {} }; } #[rustfmt::skip] gen!(impl); gen!(fn bar); // When the macro is in a different file, the suggestion spans can't be combined properly // and should not cause an ICE // See #2707 #[macro_use] #[path = "../auxiliary/test_macro.rs"] pub mod test_macro; __implicit_hasher_test_macro!(impl<K, V> for HashMap<K, V> where V: test_macro::A); fn main() {}