Rollup merge of rust-lang#58812 - jonhoo:floor_v_trunc, r=alexcrichton

Clarify distinction between floor() and trunc() `floor()` rounds towards `-INF`, `trunc()` rounds towards 0. This PR clarifies this in the examples.
Centril · Mar 19, 2019 · 5abd9c7 · 5abd9c7
2 parents fff8586 + c5fe405
commit 5abd9c7
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Showing 2 changed files with 16 additions and 8 deletions.
diff --git a/src/libstd/f32.rs b/src/libstd/f32.rs
@@ -32,11 +32,13 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// let f = 3.99_f32;
+    /// let f = 3.7_f32;
     /// let g = 3.0_f32;
+    /// let h = -3.7_f32;
     ///
     /// assert_eq!(f.floor(), 3.0);
     /// assert_eq!(g.floor(), 3.0);
+    /// assert_eq!(h.floor(), -4.0);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -104,11 +106,13 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// let f = 3.3_f32;
-    /// let g = -3.7_f32;
+    /// let f = 3.7_f32;
+    /// let g = 3.0_f32;
+    /// let h = -3.7_f32;
     ///
     /// assert_eq!(f.trunc(), 3.0);
-    /// assert_eq!(g.trunc(), -3.0);
+    /// assert_eq!(g.trunc(), 3.0);
+    /// assert_eq!(h.trunc(), -3.0);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]

diff --git a/src/libstd/f64.rs b/src/libstd/f64.rs
@@ -32,11 +32,13 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// let f = 3.99_f64;
+    /// let f = 3.7_f64;
     /// let g = 3.0_f64;
+    /// let h = -3.7_f64;
     ///
     /// assert_eq!(f.floor(), 3.0);
     /// assert_eq!(g.floor(), 3.0);
+    /// assert_eq!(h.floor(), -4.0);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -84,11 +86,13 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// let f = 3.3_f64;
-    /// let g = -3.7_f64;
+    /// let f = 3.7_f64;
+    /// let g = 3.0_f64;
+    /// let h = -3.7_f64;
     ///
     /// assert_eq!(f.trunc(), 3.0);
-    /// assert_eq!(g.trunc(), -3.0);
+    /// assert_eq!(g.trunc(), 3.0);
+    /// assert_eq!(h.trunc(), -3.0);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]