7 files changed, 202 insertions, 0 deletions
diff --git a/src/compile_fail/cannot_collect_filtermap_data.rs b/src/compile_fail/cannot_collect_filtermap_data.rs
new file mode 100644
index 0000000..65ff875
--- /dev/null
+++ b/src/compile_fail/cannot_collect_filtermap_data.rs
@@ -0,0 +1,16 @@
+/*! ```compile_fail,E0599
+
+use rayon::prelude::*;
+
+// zip requires data of exact size, but filter yields only bounded
+// size, so check that we cannot apply it.
+
+fn main() {
+    let a: Vec<usize> = (0..1024).collect();
+    let mut v = vec![];
+    a.par_iter()
+     .filter_map(|&x| Some(x as f32))
+     .collect_into_vec(&mut v); //~ ERROR no method
+}
+
+``` */
diff --git a/src/compile_fail/cannot_zip_filtered_data.rs b/src/compile_fail/cannot_zip_filtered_data.rs
new file mode 100644
index 0000000..de43fca
--- /dev/null
+++ b/src/compile_fail/cannot_zip_filtered_data.rs
@@ -0,0 +1,16 @@
+/*! ```compile_fail,E0277
+
+use rayon::prelude::*;
+
+// zip requires data of exact size, but filter yields only bounded
+// size, so check that we cannot apply it.
+
+fn main() {
+    let mut a: Vec<usize> = (0..1024).rev().collect();
+    let b: Vec<usize> = (0..1024).collect();
+
+    a.par_iter()
+     .zip(b.par_iter().filter(|&&x| x > 3)); //~ ERROR
+}
+
+``` */
diff --git a/src/compile_fail/cell_par_iter.rs b/src/compile_fail/cell_par_iter.rs
new file mode 100644
index 0000000..4af04b1
--- /dev/null
+++ b/src/compile_fail/cell_par_iter.rs
@@ -0,0 +1,15 @@
+/*! ```compile_fail,E0277
+
+// Check that we can't use the par-iter API to access contents of a `Cell`.
+
+use rayon::prelude::*;
+use std::cell::Cell;
+
+fn main() {
+    let c = Cell::new(42_i32);
+    (0_i32..1024).into_par_iter()
+             .map(|_| c.get()) //~ ERROR E0277
+             .min();
+}
+
+``` */
diff --git a/src/compile_fail/mod.rs b/src/compile_fail/mod.rs
new file mode 100644
index 0000000..13209a4
--- /dev/null
+++ b/src/compile_fail/mod.rs
@@ -0,0 +1,7 @@
+// These modules contain `compile_fail` doc tests.
+mod cannot_collect_filtermap_data;
+mod cannot_zip_filtered_data;
+mod cell_par_iter;
+mod must_use;
+mod no_send_par_iter;
+mod rc_par_iter;
diff --git a/src/compile_fail/must_use.rs b/src/compile_fail/must_use.rs
new file mode 100644
index 0000000..ac50a62
--- /dev/null
+++ b/src/compile_fail/must_use.rs
@@ -0,0 +1,67 @@
+// Check that we are flagged for ignoring `must_use` parallel adaptors.
+// (unfortunately there's no error code for `unused_must_use`)
+
+macro_rules! must_use {
+    ($( $name:ident #[$expr:meta] )*) => {$(
+        /// First sanity check that the expression is OK.
+        ///
+        /// ```
+        /// #![deny(unused_must_use)]
+        ///
+        /// use rayon::prelude::*;
+        ///
+        /// let v: Vec<_> = (0..100).map(Some).collect();
+        /// let _ =
+        #[$expr]
+        /// ```
+        ///
+        /// Now trigger the `must_use`.
+        ///
+        /// ```compile_fail
+        /// #![deny(unused_must_use)]
+        ///
+        /// use rayon::prelude::*;
+        ///
+        /// let v: Vec<_> = (0..100).map(Some).collect();
+        #[$expr]
+        /// ```
+        mod $name {}
+    )*}
+}
+
+must_use! {
+    step_by             /** v.par_iter().step_by(2); */
+    chain               /** v.par_iter().chain(&v); */
+    chunks              /** v.par_iter().chunks(2); */
+    cloned              /** v.par_iter().cloned(); */
+    copied              /** v.par_iter().copied(); */
+    enumerate           /** v.par_iter().enumerate(); */
+    filter              /** v.par_iter().filter(|_| true); */
+    filter_map          /** v.par_iter().filter_map(|x| *x); */
+    flat_map            /** v.par_iter().flat_map(|x| *x); */
+    flat_map_iter       /** v.par_iter().flat_map_iter(|x| *x); */
+    flatten             /** v.par_iter().flatten(); */
+    flatten_iter        /** v.par_iter().flatten_iter(); */
+    fold                /** v.par_iter().fold(|| 0, |x, _| x); */
+    fold_with           /** v.par_iter().fold_with(0, |x, _| x); */
+    try_fold            /** v.par_iter().try_fold(|| 0, |x, _| Some(x)); */
+    try_fold_with       /** v.par_iter().try_fold_with(0, |x, _| Some(x)); */
+    inspect             /** v.par_iter().inspect(|_| {}); */
+    interleave          /** v.par_iter().interleave(&v); */
+    interleave_shortest /** v.par_iter().interleave_shortest(&v); */
+    intersperse         /** v.par_iter().intersperse(&None); */
+    map                 /** v.par_iter().map(|x| x); */
+    map_with            /** v.par_iter().map_with(0, |_, x| x); */
+    map_init            /** v.par_iter().map_init(|| 0, |_, x| x); */
+    panic_fuse          /** v.par_iter().panic_fuse(); */
+    positions           /** v.par_iter().positions(|_| true); */
+    rev                 /** v.par_iter().rev(); */
+    skip                /** v.par_iter().skip(1); */
+    take                /** v.par_iter().take(1); */
+    update              /** v.par_iter().update(|_| {}); */
+    while_some          /** v.par_iter().cloned().while_some(); */
+    with_max_len        /** v.par_iter().with_max_len(1); */
+    with_min_len        /** v.par_iter().with_min_len(1); */
+    zip                 /** v.par_iter().zip(&v); */
+    zip_eq              /** v.par_iter().zip_eq(&v); */
+}
diff --git a/src/compile_fail/no_send_par_iter.rs b/src/compile_fail/no_send_par_iter.rs
new file mode 100644
index 0000000..1362c98
--- /dev/null
+++ b/src/compile_fail/no_send_par_iter.rs
@@ -0,0 +1,64 @@
+// Check that `!Send` types fail early.
+
+/** ```compile_fail,E0277
+
+use rayon::prelude::*;
+use std::ptr::null;
+
+#[derive(Copy, Clone)]
+struct NoSend(*const ());
+
+unsafe impl Sync for NoSend {}
+
+fn main() {
+    let x = Some(NoSend(null()));
+
+    x.par_iter()
+        .map(|&x| x) //~ ERROR
+        .count(); //~ ERROR
+}
+
+``` */
+mod map {}
+
+/** ```compile_fail,E0277
+
+use rayon::prelude::*;
+use std::ptr::null;
+
+#[derive(Copy, Clone)]
+struct NoSend(*const ());
+
+unsafe impl Sync for NoSend {}
+
+fn main() {
+    let x = Some(NoSend(null()));
+
+    x.par_iter()
+        .filter_map(|&x| Some(x)) //~ ERROR
+        .count(); //~ ERROR
+}
+
+``` */
+mod filter_map {}
+
+/** ```compile_fail,E0277
+
+use rayon::prelude::*;
+use std::ptr::null;
+
+#[derive(Copy, Clone)]
+struct NoSend(*const ());
+
+unsafe impl Sync for NoSend {}
+
+fn main() {
+    let x = Some(NoSend(null()));
+
+    x.par_iter()
+        .cloned() //~ ERROR
+        .count(); //~ ERROR
+}
+
+``` */
+mod cloned {}
diff --git a/src/compile_fail/rc_par_iter.rs b/src/compile_fail/rc_par_iter.rs
new file mode 100644
index 0000000..feaedb3
--- /dev/null
+++ b/src/compile_fail/rc_par_iter.rs
@@ -0,0 +1,17 @@
+/*! ```compile_fail,E0599
+
+// Check that we can't use the par-iter API to access contents of an
+// `Rc`.
+
+use rayon::prelude::*;
+use std::rc::Rc;
+
+fn main() {
+    let x = vec![Rc::new(22), Rc::new(23)];
+    let mut y = vec![];
+    x.into_par_iter() //~ ERROR no method named `into_par_iter`
+     .map(|rc| *rc)
+     .collect_into_vec(&mut y);
+}
+
+``` */