From 33b74618b673a3c9b9072ecf7f880a98435b7f82 Mon Sep 17 00:00:00 2001
From: Jim Turner <git@turner.link>
Date: Mon, 23 Sep 2019 20:40:07 -0400
Subject: [PATCH 1/3] Debug-panic in clamp_min/max if min/max is NAN

This also improves the docs for `clamp`, `clamp_min`, and `clamp_max`.
---
 src/lib.rs | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 1bc9e7b..7146002 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -364,6 +364,8 @@ float_trait_impl!(Num for f32 f64);
 ///  If input is less than min then this returns min.
 ///  If input is greater than max then this returns max.
 ///  Otherwise this returns input.
+///
+/// **Panics** in debug mode if `!(min <= max)`.
 #[inline]
 pub fn clamp<T: PartialOrd>(input: T, min: T, max: T) -> T {
     debug_assert!(min <= max, "min must be less than or equal to max");
@@ -381,8 +383,11 @@ pub fn clamp<T: PartialOrd>(input: T, min: T, max: T) -> T {
 ///  If input is less than min then this returns min.
 ///  Otherwise this returns input.
 ///  `clamp_min(std::f32::NAN, 1.0)` preserves `NAN` different from `f32::min(std::f32::NAN, 1.0)`.
+///
+/// **Panics** in debug mode if `!(min == min)`. (This occurs if `min` is `NAN`.)
 #[inline]
 pub fn clamp_min<T: PartialOrd>(input: T, min: T) -> T {
+    debug_assert!(min == min, "min must not be NAN");
     if input < min {
         min
     } else {
@@ -395,8 +400,11 @@ pub fn clamp_min<T: PartialOrd>(input: T, min: T) -> T {
 ///  If input is greater than max then this returns max.
 ///  Otherwise this returns input.
 ///  `clamp_max(std::f32::NAN, 1.0)` preserves `NAN` different from `f32::max(std::f32::NAN, 1.0)`.
+///
+/// **Panics** in debug mode if `!(max == max)`. (This occurs if `max` is `NAN`.)
 #[inline]
 pub fn clamp_max<T: PartialOrd>(input: T, max: T) -> T {
+    debug_assert!(max == max, "max must not be NAN");
     if input > max {
         max
     } else {
@@ -428,6 +436,28 @@ fn clamp_test() {
     assert!(clamp_max(::core::f32::NAN, 1.0).is_nan());
 }
 
+#[test]
+fn clamp_nan_bound() {
+    /// When debug assertions are enabled, checks that the expression panics.
+    macro_rules! assert_debug_panics {
+        ($body:expr) => {
+            if cfg!(debug_assertions) {
+                if let Ok(v) = ::std::panic::catch_unwind(|| $body) {
+                    panic!(
+                        "assertion failed: should_panic; non-panicking result: {:?}",
+                        v
+                    );
+                }
+            }
+        };
+    }
+    assert_debug_panics!(clamp(0., ::core::f32::NAN, 1.));
+    assert_debug_panics!(clamp(0., -1., ::core::f32::NAN));
+    assert_debug_panics!(clamp(0., ::core::f32::NAN, ::core::f32::NAN));
+    assert_debug_panics!(clamp_min(0., ::core::f32::NAN));
+    assert_debug_panics!(clamp_max(0., ::core::f32::NAN));
+}
+
 #[test]
 fn from_str_radix_unwrap() {
     // The Result error must impl Debug to allow unwrap()

From d02f1667652fd26b64514d02d79a10892c96c805 Mon Sep 17 00:00:00 2001
From: Jim Turner <git@turner.link>
Date: Mon, 23 Sep 2019 22:12:35 -0400
Subject: [PATCH 2/3] Restrict panic testing to when std is enabled

---
 src/lib.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 7146002..28855f4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -438,10 +438,12 @@ fn clamp_test() {
 
 #[test]
 fn clamp_nan_bound() {
-    /// When debug assertions are enabled, checks that the expression panics.
+    /// When debug assertions and the `std` feature are enabled, checks that
+    /// the expression panics.
     macro_rules! assert_debug_panics {
         ($body:expr) => {
-            if cfg!(debug_assertions) {
+            #[cfg(all(debug_assertions, feature = "std"))]
+            {
                 if let Ok(v) = ::std::panic::catch_unwind(|| $body) {
                     panic!(
                         "assertion failed: should_panic; non-panicking result: {:?}",

From 987ed8fd3891823ef8d441b54b6dd3643cd8330a Mon Sep 17 00:00:00 2001
From: Jim Turner <git@turner.link>
Date: Mon, 23 Sep 2019 22:21:33 -0400
Subject: [PATCH 3/3] Split clamp panicking test into separate tests

---
 src/lib.rs | 53 ++++++++++++++++++++++++++++++++---------------------
 1 file changed, 32 insertions(+), 21 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 28855f4..73fcdb3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -437,27 +437,38 @@ fn clamp_test() {
 }
 
 #[test]
-fn clamp_nan_bound() {
-    /// When debug assertions and the `std` feature are enabled, checks that
-    /// the expression panics.
-    macro_rules! assert_debug_panics {
-        ($body:expr) => {
-            #[cfg(all(debug_assertions, feature = "std"))]
-            {
-                if let Ok(v) = ::std::panic::catch_unwind(|| $body) {
-                    panic!(
-                        "assertion failed: should_panic; non-panicking result: {:?}",
-                        v
-                    );
-                }
-            }
-        };
-    }
-    assert_debug_panics!(clamp(0., ::core::f32::NAN, 1.));
-    assert_debug_panics!(clamp(0., -1., ::core::f32::NAN));
-    assert_debug_panics!(clamp(0., ::core::f32::NAN, ::core::f32::NAN));
-    assert_debug_panics!(clamp_min(0., ::core::f32::NAN));
-    assert_debug_panics!(clamp_max(0., ::core::f32::NAN));
+#[should_panic]
+#[cfg(debug_assertions)]
+fn clamp_nan_min() {
+    clamp(0., ::core::f32::NAN, 1.);
+}
+
+#[test]
+#[should_panic]
+#[cfg(debug_assertions)]
+fn clamp_nan_max() {
+    clamp(0., -1., ::core::f32::NAN);
+}
+
+#[test]
+#[should_panic]
+#[cfg(debug_assertions)]
+fn clamp_nan_min_max() {
+    clamp(0., ::core::f32::NAN, ::core::f32::NAN);
+}
+
+#[test]
+#[should_panic]
+#[cfg(debug_assertions)]
+fn clamp_min_nan_min() {
+    clamp_min(0., ::core::f32::NAN);
+}
+
+#[test]
+#[should_panic]
+#[cfg(debug_assertions)]
+fn clamp_max_nan_max() {
+    clamp_max(0., ::core::f32::NAN);
 }
 
 #[test]