Auto merge of #76804 - tmandry:rollup-nwntt3q, r=tmandry

Rollup of 16 pull requests

Successful merges:

 - #75026 (Add array_windows fn)
 - #76642 (Do not lint ignored private doc tests)
 - #76719 (Change error message for ty param in const)
 - #76721 (Use intra-doc links in `core::mem`)
 - #76728 (Add a comment why `extern crate` is necessary for rustdoc)
 - #76735 (Remove unnecessary `clone()`s in bootstrap)
 - #76741 (Avoid printing dry run timings)
 - #76747 (Add missing code examples in libcore)
 - #76756 (fix a couple of stylistic clippy warnings)
 - #76758 ([fuchsia] Propagate the userspace UTC clock)
 - #76759 (Fix stabilization marker for future_readiness_fns)
 - #76760 (don't lazily evaluate some trivial values for Option::None replacements (clippy::unnecessary_lazy_evaluations))
 - #76764 (Update books)
 - #76775 (Strip a single leading tab when rendering dataflow diffs)
 - #76778 (Simplify iter fuse struct doc)
 - #76794 (Make graphviz font configurable)

Failed merges:

r? `@ghost`

19 files changed, 135 insertions, 66 deletions

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 140507eab66..d2537d65e67 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -1209,7 +1209,7 @@ impl<'a> Builder<'a> {
             cargo.env(format!("CC_{}", target.triple), &cc);
 
             let cflags = self.cflags(target, GitRepo::Rustc).join(" ");
-            cargo.env(format!("CFLAGS_{}", target.triple), cflags.clone());
+            cargo.env(format!("CFLAGS_{}", target.triple), &cflags);
 
             if let Some(ar) = self.ar(target) {
                 let ranlib = format!("{} s", ar.display());
@@ -1394,7 +1394,7 @@ impl<'a> Builder<'a> {
             (out, dur - deps)
         };
 
-        if self.config.print_step_timings {
+        if self.config.print_step_timings && !self.config.dry_run {
             println!("[TIMING] {:?} -- {}.{:03}", step, dur.as_secs(), dur.subsec_millis());
         }
 
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 30c9e012cd6..7e2cb772186 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -500,6 +500,7 @@ impl Config {
 
     pub fn parse(args: &[String]) -> Config {
         let flags = Flags::parse(&args);
+
         let mut config = Config::default_opts();
         config.exclude = flags.exclude;
         config.rustc_error_format = flags.rustc_error_format;
@@ -551,14 +552,14 @@ impl Config {
         let has_targets = build.target.is_some() || flags.target.is_some();
         config.skip_only_host_steps = !has_hosts && has_targets;
 
-        config.hosts = if let Some(arg_host) = flags.host.clone() {
+        config.hosts = if let Some(arg_host) = flags.host {
             arg_host
         } else if let Some(file_host) = build.host {
             file_host.iter().map(|h| TargetSelection::from_user(h)).collect()
         } else {
             vec![config.build]
         };
-        config.targets = if let Some(arg_target) = flags.target.clone() {
+        config.targets = if let Some(arg_target) = flags.target {
             arg_target
         } else if let Some(file_target) = build.target {
             file_target.iter().map(|h| TargetSelection::from_user(h)).collect()
@@ -628,14 +629,14 @@ impl Config {
 
         config.verbose = cmp::max(config.verbose, flags.verbose);
 
-        if let Some(ref install) = toml.install {
-            config.prefix = install.prefix.clone().map(PathBuf::from);
-            config.sysconfdir = install.sysconfdir.clone().map(PathBuf::from);
-            config.datadir = install.datadir.clone().map(PathBuf::from);
-            config.docdir = install.docdir.clone().map(PathBuf::from);
-            set(&mut config.bindir, install.bindir.clone().map(PathBuf::from));
-            config.libdir = install.libdir.clone().map(PathBuf::from);
-            config.mandir = install.mandir.clone().map(PathBuf::from);
+        if let Some(install) = toml.install {
+            config.prefix = install.prefix.map(PathBuf::from);
+            config.sysconfdir = install.sysconfdir.map(PathBuf::from);
+            config.datadir = install.datadir.map(PathBuf::from);
+            config.docdir = install.docdir.map(PathBuf::from);
+            set(&mut config.bindir, install.bindir.map(PathBuf::from));
+            config.libdir = install.libdir.map(PathBuf::from);
+            config.mandir = install.mandir.map(PathBuf::from);
         }
 
         // We want the llvm-skip-rebuild flag to take precedence over the
@@ -658,7 +659,7 @@ impl Config {
         let mut optimize = None;
         let mut ignore_git = None;
 
-        if let Some(ref llvm) = toml.llvm {
+        if let Some(llvm) = toml.llvm {
             match llvm.ccache {
                 Some(StringOrBool::String(ref s)) => config.ccache = Some(s.to_string()),
                 Some(StringOrBool::Bool(true)) => {
@@ -726,7 +727,7 @@ impl Config {
             }
         }
 
-        if let Some(ref rust) = toml.rust {
+        if let Some(rust) = toml.rust {
             debug = rust.debug;
             debug_assertions = rust.debug_assertions;
             debug_assertions_std = rust.debug_assertions_std;
@@ -746,7 +747,7 @@ impl Config {
             set(&mut config.test_compare_mode, rust.test_compare_mode);
             set(&mut config.llvm_libunwind, rust.llvm_libunwind);
             set(&mut config.backtrace, rust.backtrace);
-            set(&mut config.channel, rust.channel.clone());
+            set(&mut config.channel, rust.channel);
             set(&mut config.rust_dist_src, rust.dist_src);
             set(&mut config.verbose_tests, rust.verbose_tests);
             // in the case "false" is set explicitly, do not overwrite the command line args
@@ -757,9 +758,9 @@ impl Config {
             set(&mut config.lld_enabled, rust.lld);
             set(&mut config.llvm_tools_enabled, rust.llvm_tools);
             config.rustc_parallel = rust.parallel_compiler.unwrap_or(false);
-            config.rustc_default_linker = rust.default_linker.clone();
-            config.musl_root = rust.musl_root.clone().map(PathBuf::from);
-            config.save_toolstates = rust.save_toolstates.clone().map(PathBuf::from);
+            config.rustc_default_linker = rust.default_linker;
+            config.musl_root = rust.musl_root.map(PathBuf::from);
+            config.save_toolstates = rust.save_toolstates.map(PathBuf::from);
             set(&mut config.deny_warnings, flags.deny_warnings.or(rust.deny_warnings));
             set(&mut config.backtrace_on_ice, rust.backtrace_on_ice);
             set(&mut config.rust_verify_llvm_ir, rust.verify_llvm_ir);
@@ -776,9 +777,9 @@ impl Config {
             config.rust_codegen_units_std = rust.codegen_units_std.map(threads_from_config);
         }
 
-        if let Some(ref t) = toml.target {
+        if let Some(t) = toml.target {
             for (triple, cfg) in t {
-                let mut target = Target::from_triple(triple);
+                let mut target = Target::from_triple(&triple);
 
                 if let Some(ref s) = cfg.llvm_config {
                     target.llvm_config = Some(config.src.join(s));
@@ -792,18 +793,18 @@ impl Config {
                 if let Some(s) = cfg.no_std {
                     target.no_std = s;
                 }
-                target.cc = cfg.cc.clone().map(PathBuf::from);
-                target.cxx = cfg.cxx.clone().map(PathBuf::from);
-                target.ar = cfg.ar.clone().map(PathBuf::from);
-                target.ranlib = cfg.ranlib.clone().map(PathBuf::from);
-                target.linker = cfg.linker.clone().map(PathBuf::from);
+                target.cc = cfg.cc.map(PathBuf::from);
+                target.cxx = cfg.cxx.map(PathBuf::from);
+                target.ar = cfg.ar.map(PathBuf::from);
+                target.ranlib = cfg.ranlib.map(PathBuf::from);
+                target.linker = cfg.linker.map(PathBuf::from);
                 target.crt_static = cfg.crt_static;
-                target.musl_root = cfg.musl_root.clone().map(PathBuf::from);
-                target.musl_libdir = cfg.musl_libdir.clone().map(PathBuf::from);
-                target.wasi_root = cfg.wasi_root.clone().map(PathBuf::from);
-                target.qemu_rootfs = cfg.qemu_rootfs.clone().map(PathBuf::from);
+                target.musl_root = cfg.musl_root.map(PathBuf::from);
+                target.musl_libdir = cfg.musl_libdir.map(PathBuf::from);
+                target.wasi_root = cfg.wasi_root.map(PathBuf::from);
+                target.qemu_rootfs = cfg.qemu_rootfs.map(PathBuf::from);
 
-                config.target_config.insert(TargetSelection::from_user(triple), target);
+                config.target_config.insert(TargetSelection::from_user(&triple), target);
             }
         }
 
@@ -821,10 +822,10 @@ impl Config {
             build_target.llvm_filecheck = Some(ci_llvm_bin.join(exe("FileCheck", config.build)));
         }
 
-        if let Some(ref t) = toml.dist {
-            config.dist_sign_folder = t.sign_folder.clone().map(PathBuf::from);
-            config.dist_gpg_password_file = t.gpg_password_file.clone().map(PathBuf::from);
-            config.dist_upload_addr = t.upload_addr.clone();
+        if let Some(t) = toml.dist {
+            config.dist_sign_folder = t.sign_folder.map(PathBuf::from);
+            config.dist_gpg_password_file = t.gpg_password_file.map(PathBuf::from);
+            config.dist_upload_addr = t.upload_addr;
             set(&mut config.rust_dist_src, t.src_tarball);
             set(&mut config.missing_tools, t.missing_tools);
         }
diff --git a/src/bootstrap/format.rs b/src/bootstrap/format.rs
index 6f93082e675..0ae9f9712d5 100644
--- a/src/bootstrap/format.rs
+++ b/src/bootstrap/format.rs
@@ -105,15 +105,13 @@ pub fn format(build: &Build, check: bool) {
         eprintln!("./x.py fmt is not supported on this channel");
         std::process::exit(1);
     });
-    let src = build.src.clone();
-    let walker = WalkBuilder::new(&build.src).types(matcher).overrides(ignore_fmt).build_parallel();
+    let src = &build.src;
+    let walker = WalkBuilder::new(src).types(matcher).overrides(ignore_fmt).build_parallel();
     walker.run(|| {
-        let src = src.clone();
-        let rustfmt_path = rustfmt_path.clone();
         Box::new(move |entry| {
             let entry = t!(entry);
             if entry.file_type().map_or(false, |t| t.is_file()) {
-                rustfmt(&src, &rustfmt_path, &entry.path(), check);
+                rustfmt(src, &rustfmt_path, &entry.path(), check);
             }
             ignore::WalkState::Continue
         })
diff --git a/src/bootstrap/sanity.rs b/src/bootstrap/sanity.rs
index 4d6612a376a..6826d177a4a 100644
--- a/src/bootstrap/sanity.rs
+++ b/src/bootstrap/sanity.rs
@@ -30,8 +30,8 @@ impl Finder {
         Self { cache: HashMap::new(), path: env::var_os("PATH").unwrap_or_default() }
     }
 
-    pub fn maybe_have<S: AsRef<OsStr>>(&mut self, cmd: S) -> Option<PathBuf> {
-        let cmd: OsString = cmd.as_ref().into();
+    pub fn maybe_have<S: Into<OsString>>(&mut self, cmd: S) -> Option<PathBuf> {
+        let cmd: OsString = cmd.into();
         let path = &self.path;
         self.cache
             .entry(cmd.clone())
diff --git a/src/doc/book b/src/doc/book
-Subproject e5ed97128302d5fa45dbac0e64426bc7649a558
+Subproject cb28dee95e5e50b793e6ba9291c5d1568d3ad72
diff --git a/src/doc/nomicon b/src/doc/nomicon
-Subproject 25854752549d44d76fbd7650e17cb4f167a0b8f
+Subproject 6e57e64501f61873ab80cb78a07180a22751a5d
diff --git a/src/doc/reference b/src/doc/reference
-Subproject 25391dba46262f882fa846beefaff54a966a8fa
+Subproject 56a13c082ee90736c08d6abdcd90462517b703d
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 73a783d5406..7762e8f8d4f 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -16,6 +16,16 @@
 
 #[macro_use]
 extern crate lazy_static;
+#[macro_use]
+extern crate tracing;
+
+// N.B. these need `extern crate` even in 2018 edition
+// because they're loaded implicitly from the sysroot.
+// The reason they're loaded from the sysroot is because
+// the rustdoc artifacts aren't stored in rustc's cargo target directory.
+// So if `rustc` was specified in Cargo.toml, this would spuriously rebuild crates.
+//
+// Dependencies listed in Cargo.toml do not need `extern crate`.
 extern crate rustc_ast;
 extern crate rustc_ast_pretty;
 extern crate rustc_attr;
@@ -42,8 +52,6 @@ extern crate rustc_target;
 extern crate rustc_trait_selection;
 extern crate rustc_typeck;
 extern crate test as testing;
-#[macro_use]
-extern crate tracing;
 
 use std::default::Default;
 use std::env;
diff --git a/src/librustdoc/passes/doc_test_lints.rs b/src/librustdoc/passes/doc_test_lints.rs
index cbbe86dc433..78af9f9b856 100644
--- a/src/librustdoc/passes/doc_test_lints.rs
+++ b/src/librustdoc/passes/doc_test_lints.rs
@@ -8,7 +8,7 @@ use crate::clean;
 use crate::clean::*;
 use crate::core::DocContext;
 use crate::fold::DocFolder;
-use crate::html::markdown::{find_testable_code, ErrorCodes, LangString};
+use crate::html::markdown::{find_testable_code, ErrorCodes, Ignore, LangString};
 use rustc_session::lint;
 
 pub const CHECK_PRIVATE_ITEMS_DOC_TESTS: Pass = Pass {
@@ -48,15 +48,11 @@ pub(crate) struct Tests {
     pub(crate) found_tests: usize,
 }
 
-impl Tests {
-    pub(crate) fn new() -> Tests {
-        Tests { found_tests: 0 }
-    }
-}
-
 impl crate::doctest::Tester for Tests {
-    fn add_test(&mut self, _: String, _: LangString, _: usize) {
-        self.found_tests += 1;
+    fn add_test(&mut self, _: String, config: LangString, _: usize) {
+        if config.rust && config.ignore == Ignore::None {
+            self.found_tests += 1;
+        }
     }
 }
 
@@ -85,7 +81,7 @@ pub fn look_for_tests<'tcx>(cx: &DocContext<'tcx>, dox: &str, item: &Item) {
         }
     };
 
-    let mut tests = Tests::new();
+    let mut tests = Tests { found_tests: 0 };
 
     find_testable_code(&dox, &mut tests, ErrorCodes::No, false, None);
 
diff --git a/src/test/rustdoc-ui/coverage/doc-examples.stdout b/src/test/rustdoc-ui/coverage/doc-examples.stdout
index 10ed13c9ff5..8188740f873 100644
--- a/src/test/rustdoc-ui/coverage/doc-examples.stdout
+++ b/src/test/rustdoc-ui/coverage/doc-examples.stdout
@@ -1,7 +1,7 @@
 +-------------------------------------+------------+------------+------------+------------+
 | File                                | Documented | Percentage |   Examples | Percentage |
 +-------------------------------------+------------+------------+------------+------------+
-| ...tdoc-ui/coverage/doc-examples.rs |          4 |     100.0% |          2 |      50.0% |
+| ...tdoc-ui/coverage/doc-examples.rs |          4 |     100.0% |          1 |      25.0% |
 +-------------------------------------+------------+------------+------------+------------+
-| Total                               |          4 |     100.0% |          2 |      50.0% |
+| Total                               |          4 |     100.0% |          1 |      25.0% |
 +-------------------------------------+------------+------------+------------+------------+
diff --git a/src/test/rustdoc-ui/private-doc-test.rs b/src/test/rustdoc-ui/private-doc-test.rs
new file mode 100644
index 00000000000..379fa45f9fa
--- /dev/null
+++ b/src/test/rustdoc-ui/private-doc-test.rs
@@ -0,0 +1,12 @@
+// check-pass
+
+#![deny(private_doc_tests)]
+
+mod foo {
+    /// private doc test
+    ///
+    /// ```ignore (used for testing ignored doc tests)
+    /// assert!(false);
+    /// ```
+    fn bar() {}
+}
diff --git a/src/test/ui/const-generics/issues/issue-64494.min.stderr b/src/test/ui/const-generics/issues/issue-64494.min.stderr
index 69fe0974a79..07822f86f52 100644
--- a/src/test/ui/const-generics/issues/issue-64494.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-64494.min.stderr
@@ -4,7 +4,7 @@ error: generic parameters must not be used inside of non trivial constant values
 LL | impl<T: Foo> MyTrait for T where Is<{T::VAL == 5}>: True {}
    |                                      ^^^^^^ non-trivial anonymous constants must not depend on the parameter `T`
    |
-   = help: it is currently only allowed to use either `T` or `{ T }` as generic constants
+   = note: type parameters are currently not permitted in anonymous constants
 
 error: generic parameters must not be used inside of non trivial constant values
   --> $DIR/issue-64494.rs:19:38
@@ -12,7 +12,7 @@ error: generic parameters must not be used inside of non trivial constant values
 LL | impl<T: Foo> MyTrait for T where Is<{T::VAL == 6}>: True {}
    |                                      ^^^^^^ non-trivial anonymous constants must not depend on the parameter `T`
    |
-   = help: it is currently only allowed to use either `T` or `{ T }` as generic constants
+   = note: type parameters are currently not permitted in anonymous constants
 
 error[E0119]: conflicting implementations of trait `MyTrait`:
   --> $DIR/issue-64494.rs:19:1
diff --git a/src/test/ui/const-generics/issues/issue-67739.min.stderr b/src/test/ui/const-generics/issues/issue-67739.min.stderr
index 1254ee7239d..68f1733decb 100644
--- a/src/test/ui/const-generics/issues/issue-67739.min.stderr
+++ b/src/test/ui/const-generics/issues/issue-67739.min.stderr
@@ -4,7 +4,7 @@ error: generic parameters must not be used inside of non trivial constant values
 LL |         [0u8; mem::size_of::<Self::Associated>()];
    |                              ^^^^^^^^^^^^^^^^ non-trivial anonymous constants must not depend on the parameter `Self`
    |
-   = help: it is currently only allowed to use either `Self` or `{ Self }` as generic constants
+   = note: type parameters are currently not permitted in anonymous constants
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.full.stderr b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.full.stderr
new file mode 100644
index 00000000000..089937e66ca
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.full.stderr
@@ -0,0 +1,18 @@
+error: constant expression depends on a generic parameter
+  --> $DIR/issue-76701-ty-param-in-const.rs:6:21
+   |
+LL | fn ty_param<T>() -> [u8; std::mem::size_of::<T>()] {
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this may fail depending on what value the parameter takes
+
+error: constant expression depends on a generic parameter
+  --> $DIR/issue-76701-ty-param-in-const.rs:12:37
+   |
+LL | fn const_param<const N: usize>() -> [u8; N + 1] {
+   |                                     ^^^^^^^^^^^
+   |
+   = note: this may fail depending on what value the parameter takes
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr
new file mode 100644
index 00000000000..a39495e0b2d
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.min.stderr
@@ -0,0 +1,18 @@
+error: generic parameters must not be used inside of non trivial constant values
+  --> $DIR/issue-76701-ty-param-in-const.rs:6:46
+   |
+LL | fn ty_param<T>() -> [u8; std::mem::size_of::<T>()] {
+   |                                              ^ non-trivial anonymous constants must not depend on the parameter `T`
+   |
+   = note: type parameters are currently not permitted in anonymous constants
+
+error: generic parameters must not be used inside of non trivial constant values
+  --> $DIR/issue-76701-ty-param-in-const.rs:12:42
+   |
+LL | fn const_param<const N: usize>() -> [u8; N + 1] {
+   |                                          ^ non-trivial anonymous constants must not depend on the parameter `N`
+   |
+   = help: it is currently only allowed to use either `N` or `{ N }` as generic constants
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.rs b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.rs
new file mode 100644
index 00000000000..9252b592360
--- /dev/null
+++ b/src/test/ui/const-generics/issues/issue-76701-ty-param-in-const.rs
@@ -0,0 +1,18 @@
+// revisions: full min
+#![cfg_attr(full, feature(const_generics))]
+#![cfg_attr(full, allow(incomplete_features))]
+#![cfg_attr(min, feature(min_const_generics))]
+
+fn ty_param<T>() -> [u8; std::mem::size_of::<T>()] {
+    //[full]~^ ERROR constant expression depends on a generic parameter
+    //[min]~^^ ERROR generic parameters must not be used inside of non trivial constant values
+    todo!()
+}
+
+fn const_param<const N: usize>() -> [u8; N + 1] {
+    //[full]~^ ERROR constant expression depends on a generic parameter
+    //[min]~^^ ERROR generic parameters must not be used inside of non trivial constant values
+    todo!()
+}
+
+fn main() {}
diff --git a/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr b/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
index 89ce58564e4..edb77a87430 100644
--- a/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
+++ b/src/test/ui/const-generics/min_const_generics/self-ty-in-const-1.stderr
@@ -4,7 +4,7 @@ error: generic parameters must not be used inside of non trivial constant values
 LL |     fn t1() -> [u8; std::mem::size_of::<Self>()];
    |                                         ^^^^ non-trivial anonymous constants must not depend on the parameter `Self`
    |
-   = help: it is currently only allowed to use either `Self` or `{ Self }` as generic constants
+   = note: type parameters are currently not permitted in anonymous constants
 
 error: generic `Self` types are currently not permitted in anonymous constants
   --> $DIR/self-ty-in-const-1.rs:14:41
diff --git a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
index 461822a9608..e545ae8571f 100644
--- a/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
+++ b/src/test/ui/const-generics/params-in-ct-in-ty-param-lazy-norm.min.stderr
@@ -12,7 +12,7 @@ error: generic parameters must not be used inside of non trivial constant values
 LL | struct Foo<T, U = [u8; std::mem::size_of::<T>()]>(T, U);
    |                                            ^ non-trivial anonymous constants must not depend on the parameter `T`
    |
-   = help: it is currently only allowed to use either `T` or `{ T }` as generic constants
+   = note: type parameters are currently not permitted in anonymous constants
 
 error: constant values inside of type parameter defaults must not depend on generic parameters
   --> $DIR/params-in-ct-in-ty-param-lazy-norm.rs:12:21
diff --git a/src/test/ui/const-generics/type-dependent/issue-61936.rs b/src/test/ui/const-generics/type-dependent/issue-61936.rs
index 1d42afa3f84..f3b19109a7c 100644
--- a/src/test/ui/const-generics/type-dependent/issue-61936.rs
+++ b/src/test/ui/const-generics/type-dependent/issue-61936.rs
@@ -5,21 +5,21 @@
 #![cfg_attr(min, feature(min_const_generics))]
 
 trait SliceExt<T: Clone> {
-    fn array_windows<'a, const N: usize>(&'a self) -> ArrayWindows<'a, T, N>;
+    fn array_windows_example<'a, const N: usize>(&'a self) -> ArrayWindowsExample<'a, T, N>;
 }
 
 impl <T: Clone> SliceExt<T> for [T] {
-   fn array_windows<'a, const N: usize>(&'a self) -> ArrayWindows<'a, T, N> {
-       ArrayWindows{ idx: 0, slice: &self }
+   fn array_windows_example<'a, const N: usize>(&'a self) -> ArrayWindowsExample<'a, T, N> {
+       ArrayWindowsExample{ idx: 0, slice: &self }
    }
 }
 
-struct ArrayWindows<'a, T, const N: usize> {
+struct ArrayWindowsExample<'a, T, const N: usize> {
     slice: &'a [T],
     idx: usize,
 }
 
-impl <'a, T: Clone, const N: usize> Iterator for ArrayWindows<'a, T, N> {
+impl <'a, T: Clone, const N: usize> Iterator for ArrayWindowsExample<'a, T, N> {
     type Item = [T; N];
     fn next(&mut self) -> Option<Self::Item> {
         // Note: this is unsound for some `T` and not meant as an example
@@ -45,7 +45,7 @@ const FOUR: usize = 4;
 fn main() {
     let v: Vec<usize> = vec![0; 100];
 
-    for array in v.as_slice().array_windows::<FOUR>() {
+    for array in v.as_slice().array_windows_example::<FOUR>() {
         assert_eq!(array, [0, 0, 0, 0])
     }
 }