diff --git a/src/libstd/f32.rs b/src/libstd/f32.rs
index c33c8f27078..65273275a40 100644
--- a/src/libstd/f32.rs
+++ b/src/libstd/f32.rs
@@ -546,9 +546,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let x = f32::consts::FRAC_PI_2;
+    /// let x = std::f32::consts::FRAC_PI_2;
     ///
     /// let abs_difference = (x.sin() - 1.0).abs();
     ///
@@ -566,9 +564,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let x = 2.0 * f32::consts::PI;
+    /// let x = 2.0 * std::f32::consts::PI;
     ///
     /// let abs_difference = (x.cos() - 1.0).abs();
     ///
@@ -586,9 +582,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let x = f32::consts::FRAC_PI_4;
+    /// let x = std::f32::consts::FRAC_PI_4;
     /// let abs_difference = (x.tan() - 1.0).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
@@ -607,12 +601,10 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let f = f32::consts::FRAC_PI_2;
+    /// let f = std::f32::consts::FRAC_PI_2;
     ///
     /// // asin(sin(pi/2))
-    /// let abs_difference = (f.sin().asin() - f32::consts::FRAC_PI_2).abs();
+    /// let abs_difference = (f.sin().asin() - std::f32::consts::FRAC_PI_2).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -630,12 +622,10 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let f = f32::consts::FRAC_PI_4;
+    /// let f = std::f32::consts::FRAC_PI_4;
     ///
     /// // acos(cos(pi/4))
-    /// let abs_difference = (f.cos().acos() - f32::consts::FRAC_PI_4).abs();
+    /// let abs_difference = (f.cos().acos() - std::f32::consts::FRAC_PI_4).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -676,8 +666,6 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
     /// // Positive angles measured counter-clockwise
     /// // from positive x axis
     /// // -pi/4 radians (45 deg clockwise)
@@ -688,8 +676,8 @@ impl f32 {
     /// let x2 = -3.0f32;
     /// let y2 = 3.0f32;
     ///
-    /// let abs_difference_1 = (y1.atan2(x1) - (-f32::consts::FRAC_PI_4)).abs();
-    /// let abs_difference_2 = (y2.atan2(x2) - (3.0 * f32::consts::FRAC_PI_4)).abs();
+    /// let abs_difference_1 = (y1.atan2(x1) - (-std::f32::consts::FRAC_PI_4)).abs();
+    /// let abs_difference_2 = (y2.atan2(x2) - (3.0 * std::f32::consts::FRAC_PI_4)).abs();
     ///
     /// assert!(abs_difference_1 <= f32::EPSILON);
     /// assert!(abs_difference_2 <= f32::EPSILON);
@@ -707,9 +695,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let x = f32::consts::FRAC_PI_4;
+    /// let x = std::f32::consts::FRAC_PI_4;
     /// let f = x.sin_cos();
     ///
     /// let abs_difference_0 = (f.0 - x.sin()).abs();
@@ -750,9 +736,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let x = f32::consts::E - 1.0;
+    /// let x = std::f32::consts::E - 1.0;
     ///
     /// // ln(1 + (e - 1)) == ln(e) == 1
     /// let abs_difference = (x.ln_1p() - 1.0).abs();
@@ -771,9 +755,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let e = f32::consts::E;
+    /// let e = std::f32::consts::E;
     /// let x = 1.0f32;
     ///
     /// let f = x.sinh();
@@ -795,9 +777,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let e = f32::consts::E;
+    /// let e = std::f32::consts::E;
     /// let x = 1.0f32;
     /// let f = x.cosh();
     /// // Solving cosh() at 1 gives this result
@@ -819,9 +799,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let e = f32::consts::E;
+    /// let e = std::f32::consts::E;
     /// let x = 1.0f32;
     ///
     /// let f = x.tanh();
@@ -885,9 +863,7 @@ impl f32 {
     /// # Examples
     ///
     /// ```
-    /// use std::f32;
-    ///
-    /// let e = f32::consts::E;
+    /// let e = std::f32::consts::E;
     /// let f = e.tanh().atanh();
     ///
     /// let abs_difference = (f - e).abs();
diff --git a/src/libstd/f64.rs b/src/libstd/f64.rs
index 8d6d619219b..ff222fc8539 100644
--- a/src/libstd/f64.rs
+++ b/src/libstd/f64.rs
@@ -548,9 +548,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let x = f64::consts::FRAC_PI_2;
+    /// let x = std::f64::consts::FRAC_PI_2;
     ///
     /// let abs_difference = (x.sin() - 1.0).abs();
     ///
@@ -568,9 +566,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let x = 2.0 * f64::consts::PI;
+    /// let x = 2.0 * std::f64::consts::PI;
     ///
     /// let abs_difference = (x.cos() - 1.0).abs();
     ///
@@ -588,9 +584,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let x = f64::consts::FRAC_PI_4;
+    /// let x = std::f64::consts::FRAC_PI_4;
     /// let abs_difference = (x.tan() - 1.0).abs();
     ///
     /// assert!(abs_difference < 1e-14);
@@ -609,12 +603,10 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let f = f64::consts::FRAC_PI_2;
+    /// let f = std::f64::consts::FRAC_PI_2;
     ///
     /// // asin(sin(pi/2))
-    /// let abs_difference = (f.sin().asin() - f64::consts::FRAC_PI_2).abs();
+    /// let abs_difference = (f.sin().asin() - std::f64::consts::FRAC_PI_2).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -632,12 +624,10 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let f = f64::consts::FRAC_PI_4;
+    /// let f = std::f64::consts::FRAC_PI_4;
     ///
     /// // acos(cos(pi/4))
-    /// let abs_difference = (f.cos().acos() - f64::consts::FRAC_PI_4).abs();
+    /// let abs_difference = (f.cos().acos() - std::f64::consts::FRAC_PI_4).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -678,8 +668,6 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
     /// // Positive angles measured counter-clockwise
     /// // from positive x axis
     /// // -pi/4 radians (45 deg clockwise)
@@ -690,8 +678,8 @@ impl f64 {
     /// let x2 = -3.0_f64;
     /// let y2 = 3.0_f64;
     ///
-    /// let abs_difference_1 = (y1.atan2(x1) - (-f64::consts::FRAC_PI_4)).abs();
-    /// let abs_difference_2 = (y2.atan2(x2) - (3.0 * f64::consts::FRAC_PI_4)).abs();
+    /// let abs_difference_1 = (y1.atan2(x1) - (-std::f64::consts::FRAC_PI_4)).abs();
+    /// let abs_difference_2 = (y2.atan2(x2) - (3.0 * std::f64::consts::FRAC_PI_4)).abs();
     ///
     /// assert!(abs_difference_1 < 1e-10);
     /// assert!(abs_difference_2 < 1e-10);
@@ -709,9 +697,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let x = f64::consts::FRAC_PI_4;
+    /// let x = std::f64::consts::FRAC_PI_4;
     /// let f = x.sin_cos();
     ///
     /// let abs_difference_0 = (f.0 - x.sin()).abs();
@@ -752,9 +738,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let x = f64::consts::E - 1.0;
+    /// let x = std::f64::consts::E - 1.0;
     ///
     /// // ln(1 + (e - 1)) == ln(e) == 1
     /// let abs_difference = (x.ln_1p() - 1.0).abs();
@@ -773,9 +757,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let e = f64::consts::E;
+    /// let e = std::f64::consts::E;
     /// let x = 1.0_f64;
     ///
     /// let f = x.sinh();
@@ -797,9 +779,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let e = f64::consts::E;
+    /// let e = std::f64::consts::E;
     /// let x = 1.0_f64;
     /// let f = x.cosh();
     /// // Solving cosh() at 1 gives this result
@@ -821,9 +801,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let e = f64::consts::E;
+    /// let e = std::f64::consts::E;
     /// let x = 1.0_f64;
     ///
     /// let f = x.tanh();
@@ -887,9 +865,7 @@ impl f64 {
     /// # Examples
     ///
     /// ```
-    /// use std::f64;
-    ///
-    /// let e = f64::consts::E;
+    /// let e = std::f64::consts::E;
     /// let f = e.tanh().atanh();
     ///
     /// let abs_difference = (f - e).abs();