Auto merge of #63808 - Rosto75:master, r=KodrAus

A bunch of minor documentation tweaks and fixes.

7 files changed, 54 insertions, 56 deletions

diff --git a/src/liballoc/collections/vec_deque.rs b/src/liballoc/collections/vec_deque.rs
index 7315963cc8b..a4a0fbb194d 100644
--- a/src/liballoc/collections/vec_deque.rs
+++ b/src/liballoc/collections/vec_deque.rs
@@ -1810,7 +1810,7 @@ impl<T> VecDeque<T> {
         other
     }
 
-    /// Moves all the elements of `other` into `Self`, leaving `other` empty.
+    /// Moves all the elements of `other` into `self`, leaving `other` empty.
     ///
     /// # Panics
     ///
@@ -1847,7 +1847,7 @@ impl<T> VecDeque<T> {
     ///
     /// let mut buf = VecDeque::new();
     /// buf.extend(1..5);
-    /// buf.retain(|&x| x%2 == 0);
+    /// buf.retain(|&x| x % 2 == 0);
     /// assert_eq!(buf, [2, 4]);
     /// ```
     ///
diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs
index 8ff78166a9f..22e7573eca6 100644
--- a/src/libcore/num/f32.rs
+++ b/src/libcore/num/f32.rs
@@ -315,7 +315,7 @@ impl f32 {
     /// use std::f32;
     ///
     /// let x = 2.0_f32;
-    /// let abs_difference = (x.recip() - (1.0/x)).abs();
+    /// let abs_difference = (x.recip() - (1.0 / x)).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index d45c04f45af..bbe1d040780 100644
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -327,7 +327,7 @@ impl f64 {
     ///
     /// ```
     /// let x = 2.0_f64;
-    /// let abs_difference = (x.recip() - (1.0/x)).abs();
+    /// let abs_difference = (x.recip() - (1.0 / x)).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
diff --git a/src/libstd/f32.rs b/src/libstd/f32.rs
index f649170c403..e55afc2344f 100644
--- a/src/libstd/f32.rs
+++ b/src/libstd/f32.rs
@@ -236,7 +236,7 @@ impl f32 {
     /// let b = 60.0_f32;
     ///
     /// // 100.0
-    /// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
+    /// let abs_difference = (m.mul_add(x, b) - ((m * x) + b)).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -318,7 +318,7 @@ impl f32 {
     /// use std::f32;
     ///
     /// let x = 2.0_f32;
-    /// let abs_difference = (x.powi(2) - x*x).abs();
+    /// let abs_difference = (x.powi(2) - (x * x)).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -336,7 +336,7 @@ impl f32 {
     /// use std::f32;
     ///
     /// let x = 2.0_f32;
-    /// let abs_difference = (x.powf(2.0) - x*x).abs();
+    /// let abs_difference = (x.powf(2.0) - (x * x)).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -600,7 +600,7 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let x = f32::consts::PI/2.0;
+    /// let x = f32::consts::FRAC_PI_2;
     ///
     /// let abs_difference = (x.sin() - 1.0).abs();
     ///
@@ -623,7 +623,7 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let x = 2.0*f32::consts::PI;
+    /// let x = 2.0 * f32::consts::PI;
     ///
     /// let abs_difference = (x.cos() - 1.0).abs();
     ///
@@ -646,7 +646,7 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let x = f32::consts::PI / 4.0;
+    /// let x = f32::consts::FRAC_PI_4;
     /// let abs_difference = (x.tan() - 1.0).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
@@ -666,10 +666,10 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let f = f32::consts::PI / 2.0;
+    /// let f = f32::consts::FRAC_PI_2;
     ///
     /// // asin(sin(pi/2))
-    /// let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();
+    /// let abs_difference = (f.sin().asin() - f32::consts::FRAC_PI_2).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -688,10 +688,10 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let f = f32::consts::PI / 4.0;
+    /// let f = f32::consts::FRAC_PI_4;
     ///
     /// // acos(cos(pi/4))
-    /// let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();
+    /// let abs_difference = (f.cos().acos() - f32::consts::FRAC_PI_4).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
     /// ```
@@ -734,7 +734,6 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let pi = f32::consts::PI;
     /// // Positive angles measured counter-clockwise
     /// // from positive x axis
     /// // -pi/4 radians (45 deg clockwise)
@@ -745,8 +744,8 @@ impl f32 {
     /// let x2 = -3.0f32;
     /// let y2 = 3.0f32;
     ///
-    /// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
-    /// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
+    /// 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();
     ///
     /// assert!(abs_difference_1 <= f32::EPSILON);
     /// assert!(abs_difference_2 <= f32::EPSILON);
@@ -765,7 +764,7 @@ impl f32 {
     /// ```
     /// use std::f32;
     ///
-    /// let x = f32::consts::PI/4.0;
+    /// let x = f32::consts::FRAC_PI_4;
     /// let f = x.sin_cos();
     ///
     /// let abs_difference_0 = (f.0 - x.sin()).abs();
@@ -834,7 +833,7 @@ impl f32 {
     ///
     /// let f = x.sinh();
     /// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
-    /// let g = (e*e - 1.0)/(2.0*e);
+    /// let g = ((e * e) - 1.0) / (2.0 * e);
     /// let abs_difference = (f - g).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
@@ -856,7 +855,7 @@ impl f32 {
     /// let x = 1.0f32;
     /// let f = x.cosh();
     /// // Solving cosh() at 1 gives this result
-    /// let g = (e*e + 1.0)/(2.0*e);
+    /// let g = ((e * e) + 1.0) / (2.0 * e);
     /// let abs_difference = (f - g).abs();
     ///
     /// // Same result
@@ -880,7 +879,7 @@ impl f32 {
     ///
     /// let f = x.tanh();
     /// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
-    /// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
+    /// let g = (1.0 - e.powi(-2)) / (1.0 + e.powi(-2));
     /// let abs_difference = (f - g).abs();
     ///
     /// assert!(abs_difference <= f32::EPSILON);
diff --git a/src/libstd/f64.rs b/src/libstd/f64.rs
index f61630997dc..b3571026300 100644
--- a/src/libstd/f64.rs
+++ b/src/libstd/f64.rs
@@ -212,7 +212,7 @@ impl f64 {
     /// let b = 60.0_f64;
     ///
     /// // 100.0
-    /// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
+    /// let abs_difference = (m.mul_add(x, b) - ((m * x) + b)).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -291,7 +291,7 @@ impl f64 {
     ///
     /// ```
     /// let x = 2.0_f64;
-    /// let abs_difference = (x.powi(2) - x*x).abs();
+    /// let abs_difference = (x.powi(2) - (x * x)).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -307,7 +307,7 @@ impl f64 {
     ///
     /// ```
     /// let x = 2.0_f64;
-    /// let abs_difference = (x.powf(2.0) - x*x).abs();
+    /// let abs_difference = (x.powf(2.0) - (x * x)).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -537,7 +537,7 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let x = f64::consts::PI/2.0;
+    /// let x = f64::consts::FRAC_PI_2;
     ///
     /// let abs_difference = (x.sin() - 1.0).abs();
     ///
@@ -556,7 +556,7 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let x = 2.0*f64::consts::PI;
+    /// let x = 2.0 * f64::consts::PI;
     ///
     /// let abs_difference = (x.cos() - 1.0).abs();
     ///
@@ -575,7 +575,7 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let x = f64::consts::PI/4.0;
+    /// let x = f64::consts::FRAC_PI_4;
     /// let abs_difference = (x.tan() - 1.0).abs();
     ///
     /// assert!(abs_difference < 1e-14);
@@ -595,10 +595,10 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let f = f64::consts::PI / 2.0;
+    /// let f = f64::consts::FRAC_PI_2;
     ///
     /// // asin(sin(pi/2))
-    /// let abs_difference = (f.sin().asin() - f64::consts::PI / 2.0).abs();
+    /// let abs_difference = (f.sin().asin() - f64::consts::FRAC_PI_2).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -617,10 +617,10 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let f = f64::consts::PI / 4.0;
+    /// let f = f64::consts::FRAC_PI_4;
     ///
     /// // acos(cos(pi/4))
-    /// let abs_difference = (f.cos().acos() - f64::consts::PI / 4.0).abs();
+    /// let abs_difference = (f.cos().acos() - f64::consts::FRAC_PI_4).abs();
     ///
     /// assert!(abs_difference < 1e-10);
     /// ```
@@ -661,7 +661,6 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let pi = f64::consts::PI;
     /// // Positive angles measured counter-clockwise
     /// // from positive x axis
     /// // -pi/4 radians (45 deg clockwise)
@@ -672,8 +671,8 @@ impl f64 {
     /// let x2 = -3.0_f64;
     /// let y2 = 3.0_f64;
     ///
-    /// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
-    /// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
+    /// 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();
     ///
     /// assert!(abs_difference_1 < 1e-10);
     /// assert!(abs_difference_2 < 1e-10);
@@ -692,7 +691,7 @@ impl f64 {
     /// ```
     /// use std::f64;
     ///
-    /// let x = f64::consts::PI/4.0;
+    /// let x = f64::consts::FRAC_PI_4;
     /// let f = x.sin_cos();
     ///
     /// let abs_difference_0 = (f.0 - x.sin()).abs();
@@ -759,7 +758,7 @@ impl f64 {
     ///
     /// let f = x.sinh();
     /// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
-    /// let g = (e*e - 1.0)/(2.0*e);
+    /// let g = ((e * e) - 1.0) / (2.0 * e);
     /// let abs_difference = (f - g).abs();
     ///
     /// assert!(abs_difference < 1e-10);
@@ -781,7 +780,7 @@ impl f64 {
     /// let x = 1.0_f64;
     /// let f = x.cosh();
     /// // Solving cosh() at 1 gives this result
-    /// let g = (e*e + 1.0)/(2.0*e);
+    /// let g = ((e * e) + 1.0) / (2.0 * e);
     /// let abs_difference = (f - g).abs();
     ///
     /// // Same result
@@ -805,7 +804,7 @@ impl f64 {
     ///
     /// let f = x.tanh();
     /// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
-    /// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
+    /// let g = (1.0 - e.powi(-2)) / (1.0 + e.powi(-2));
     /// let abs_difference = (f - g).abs();
     ///
     /// assert!(abs_difference < 1.0e-10);
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 512839a12c0..65f4e0cafe0 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -572,8 +572,8 @@ impl CString {
     /// use std::ffi::{CString, CStr};
     ///
     /// let c_string = CString::new(b"foo".to_vec()).expect("CString::new failed");
-    /// let c_str = c_string.as_c_str();
-    /// assert_eq!(c_str,
+    /// let cstr = c_string.as_c_str();
+    /// assert_eq!(cstr,
     ///            CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed"));
     /// ```
     #[inline]
@@ -994,8 +994,8 @@ impl CStr {
     /// ```
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"hello");
-    /// assert!(c_str.is_err());
+    /// let cstr = CStr::from_bytes_with_nul(b"hello");
+    /// assert!(cstr.is_err());
     /// ```
     ///
     /// Creating a `CStr` with an interior nul byte is an error:
@@ -1003,8 +1003,8 @@ impl CStr {
     /// ```
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"he\0llo\0");
-    /// assert!(c_str.is_err());
+    /// let cstr = CStr::from_bytes_with_nul(b"he\0llo\0");
+    /// assert!(cstr.is_err());
     /// ```
     #[stable(feature = "cstr_from_bytes", since = "1.10.0")]
     pub fn from_bytes_with_nul(bytes: &[u8])
@@ -1111,8 +1111,8 @@ impl CStr {
     /// ```
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(c_str.to_bytes(), b"foo");
+    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
+    /// assert_eq!(cstr.to_bytes(), b"foo");
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -1137,8 +1137,8 @@ impl CStr {
     /// ```
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(c_str.to_bytes_with_nul(), b"foo\0");
+    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
+    /// assert_eq!(cstr.to_bytes_with_nul(), b"foo\0");
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
@@ -1164,8 +1164,8 @@ impl CStr {
     /// ```
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(c_str.to_str(), Ok("foo"));
+    /// let cstr = CStr::from_bytes_with_nul(b"foo\0").expect("CStr::from_bytes_with_nul failed");
+    /// assert_eq!(cstr.to_str(), Ok("foo"));
     /// ```
     #[stable(feature = "cstr_to_str", since = "1.4.0")]
     pub fn to_str(&self) -> Result<&str, str::Utf8Error> {
@@ -1205,9 +1205,9 @@ impl CStr {
     /// use std::borrow::Cow;
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"Hello World\0")
+    /// let cstr = CStr::from_bytes_with_nul(b"Hello World\0")
     ///                  .expect("CStr::from_bytes_with_nul failed");
-    /// assert_eq!(c_str.to_string_lossy(), Cow::Borrowed("Hello World"));
+    /// assert_eq!(cstr.to_string_lossy(), Cow::Borrowed("Hello World"));
     /// ```
     ///
     /// Calling `to_string_lossy` on a `CStr` containing invalid UTF-8:
@@ -1216,10 +1216,10 @@ impl CStr {
     /// use std::borrow::Cow;
     /// use std::ffi::CStr;
     ///
-    /// let c_str = CStr::from_bytes_with_nul(b"Hello \xF0\x90\x80World\0")
+    /// let cstr = CStr::from_bytes_with_nul(b"Hello \xF0\x90\x80World\0")
     ///                  .expect("CStr::from_bytes_with_nul failed");
     /// assert_eq!(
-    ///     c_str.to_string_lossy(),
+    ///     cstr.to_string_lossy(),
     ///     Cow::Owned(String::from("Hello �World")) as Cow<'_, str>
     /// );
     /// ```
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 1f384cbada3..6cf062d4f30 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -233,7 +233,7 @@ impl OsString {
     /// ```
     /// use std::ffi::OsString;
     ///
-    /// let mut os_string = OsString::with_capacity(10);
+    /// let os_string = OsString::with_capacity(10);
     /// assert!(os_string.capacity() >= 10);
     /// ```
     #[stable(feature = "osstring_simple_functions", since = "1.9.0")]
@@ -616,7 +616,7 @@ impl OsStr {
     /// Note that this does **not** return the number of bytes in the string in
     /// OS string form.
     ///
-    /// The length returned is that of the underlying storage used by `OsStr`;
+    /// The length returned is that of the underlying storage used by `OsStr`.
     /// As discussed in the [`OsString`] introduction, [`OsString`] and `OsStr`
     /// store strings in a form best suited for cheap inter-conversion between
     /// native-platform and Rust string forms, which may differ significantly