Add examples section which demonstrates the behaviour (specifically the sign positive aspect)

Author: bmoxb

library/core/src/convert/num.rs

@@ -174,6 +174,16 @@ impl_from! { f32, f64, #[stable(feature = "lossless_float_conv", since = "1.6.0"
 impl const From<bool> for f32 {
     /// Converts `bool` to `f32` losslessly. The resulting value is positive
     /// `0.0` for `false` and `1.0` for `true` values.
+    ///
+    /// # Examples
+    /// ```
+    /// let x: f32 = false.into();
+    /// assert_eq!(x, 0.0);
+    /// assert!(x.is_sign_positive());
+    ///
+    /// let y: f32 = true.into();
+    /// assert_eq!(y, 1.0);
+    /// ```
     #[inline]
     fn from(small: bool) -> Self {
         small as u8 as Self
@@ -184,6 +194,16 @@ impl const From<bool> for f32 {
 impl const From<bool> for f64 {
     /// Converts `bool` to `f64` losslessly. The resulting value is positive
     /// `0.0` for `false` and `1.0` for `true` values.
+    ///
+    /// # Examples
+    /// ```
+    /// let x: f64 = false.into();
+    /// assert_eq!(x, 0.0);
+    /// assert!(x.is_sign_positive());
+    ///
+    /// let y: f64 = true.into();
+    /// assert_eq!(y, 1.0);
+    /// ```
     #[inline]
     fn from(small: bool) -> Self {
         small as u8 as Self