Auto merge of rust-lang#79473 - m-ou-se:clamp-in-core, r=m-ou-se

Move {f32,f64}::clamp to core.

`clamp` was recently stabilized (tracking issue: rust-lang#44095). But although `Ord::clamp` was added in `core` (because `Ord` is in `core`), the versions for the `f32` and `f64` primitives were added in `std` (together with `floor`, `sin`, etc.), not in `core` (together with `min`, `max`, `from_bits`, etc.).

This change moves them to `core`, such that `clamp` on floats is available in `no_std` programs as well.

library/core/src/num/f32.rs

@@ -961,4 +961,39 @@ impl f32 {
 
         left.cmp(&right)
     }
+
+    /// Restrict a value to a certain interval unless it is NaN.
+    ///
+    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
+    /// less than `min`. Otherwise this returns `self`.
+    ///
+    /// Note that this function returns NaN if the initial value was NaN as
+    /// well.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// assert!((-3.0f32).clamp(-2.0, 1.0) == -2.0);
+    /// assert!((0.0f32).clamp(-2.0, 1.0) == 0.0);
+    /// assert!((2.0f32).clamp(-2.0, 1.0) == 1.0);
+    /// assert!((f32::NAN).clamp(-2.0, 1.0).is_nan());
+    /// ```
+    #[must_use = "method returns a new number and does not mutate the original value"]
+    #[stable(feature = "clamp", since = "1.50.0")]
+    #[inline]
+    pub fn clamp(self, min: f32, max: f32) -> f32 {
+        assert!(min <= max);
+        let mut x = self;
+        if x < min {
+            x = min;
+        }
+        if x > max {
+            x = max;
+        }
+        x
+    }
 }

library/core/src/num/f64.rs

@@ -975,4 +975,39 @@ impl f64 {
 
         left.cmp(&right)
     }
+
+    /// Restrict a value to a certain interval unless it is NaN.
+    ///
+    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
+    /// less than `min`. Otherwise this returns `self`.
+    ///
+    /// Note that this function returns NaN if the initial value was NaN as
+    /// well.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// assert!((-3.0f64).clamp(-2.0, 1.0) == -2.0);
+    /// assert!((0.0f64).clamp(-2.0, 1.0) == 0.0);
+    /// assert!((2.0f64).clamp(-2.0, 1.0) == 1.0);
+    /// assert!((f64::NAN).clamp(-2.0, 1.0).is_nan());
+    /// ```
+    #[must_use = "method returns a new number and does not mutate the original value"]
+    #[stable(feature = "clamp", since = "1.50.0")]
+    #[inline]
+    pub fn clamp(self, min: f64, max: f64) -> f64 {
+        assert!(min <= max);
+        let mut x = self;
+        if x < min {
+            x = min;
+        }
+        if x > max {
+            x = max;
+        }
+        x
+    }
 }

library/std/src/f32.rs

@@ -879,39 +879,4 @@ impl f32 {
     pub fn atanh(self) -> f32 {
         0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
     }
-
-    /// Restrict a value to a certain interval unless it is NaN.
-    ///
-    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
-    /// less than `min`. Otherwise this returns `self`.
-    ///
-    /// Note that this function returns NaN if the initial value was NaN as
-    /// well.
-    ///
-    /// # Panics
-    ///
-    /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// assert!((-3.0f32).clamp(-2.0, 1.0) == -2.0);
-    /// assert!((0.0f32).clamp(-2.0, 1.0) == 0.0);
-    /// assert!((2.0f32).clamp(-2.0, 1.0) == 1.0);
-    /// assert!((f32::NAN).clamp(-2.0, 1.0).is_nan());
-    /// ```
-    #[must_use = "method returns a new number and does not mutate the original value"]
-    #[stable(feature = "clamp", since = "1.50.0")]
-    #[inline]
-    pub fn clamp(self, min: f32, max: f32) -> f32 {
-        assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
-        }
-        if x > max {
-            x = max;
-        }
-        x
-    }
 }

library/std/src/f64.rs

@@ -882,41 +882,6 @@ impl f64 {
         0.5 * ((2.0 * self) / (1.0 - self)).ln_1p()
     }
 
-    /// Restrict a value to a certain interval unless it is NaN.
-    ///
-    /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
-    /// less than `min`. Otherwise this returns `self`.
-    ///
-    /// Note that this function returns NaN if the initial value was NaN as
-    /// well.
-    ///
-    /// # Panics
-    ///
-    /// Panics if `min > max`, `min` is NaN, or `max` is NaN.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// assert!((-3.0f64).clamp(-2.0, 1.0) == -2.0);
-    /// assert!((0.0f64).clamp(-2.0, 1.0) == 0.0);
-    /// assert!((2.0f64).clamp(-2.0, 1.0) == 1.0);
-    /// assert!((f64::NAN).clamp(-2.0, 1.0).is_nan());
-    /// ```
-    #[must_use = "method returns a new number and does not mutate the original value"]
-    #[stable(feature = "clamp", since = "1.50.0")]
-    #[inline]
-    pub fn clamp(self, min: f64, max: f64) -> f64 {
-        assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
-        }
-        if x > max {
-            x = max;
-        }
-        x
-    }
-
     // Solaris/Illumos requires a wrapper around log, log2, and log10 functions
     // because of their non-standard behavior (e.g., log(-n) returns -Inf instead
     // of expected NaN).