Fix comment formatting

src/libcore/mem.rs

@@ -403,10 +403,8 @@ pub fn from_be32(x: u32) -> u32 { ByteOrder::from_big_endian(x) }
 #[stable]
 pub fn from_be64(x: u64) -> u64 { ByteOrder::from_big_endian(x) }
 
-/**
+/// Swap the values at two mutable locations of the same type, without
- * Swap the values at two mutable locations of the same type, without
+/// deinitialising or copying either one.
- * deinitialising or copying either one.
- */
 #[inline]
 #[stable]
 pub fn swap<T>(x: &mut T, y: &mut T) {
@@ -425,42 +423,40 @@ pub fn swap<T>(x: &mut T, y: &mut T) {
     }
 }
 
-/**
+/// Replace the value at a mutable location with a new one, returning the old
- * Replace the value at a mutable location with a new one, returning the old
+/// value, without deinitialising or copying either one.
- * value, without deinitialising or copying either one.
+///
- *
+/// This is primarily used for transferring and swapping ownership of a value
- * This is primarily used for transferring and swapping ownership of a value
+/// in a mutable location. For example, this function allows consumption of
- * in a mutable location. For example, this function allows consumption of
+/// one field of a struct by replacing it with another value. The normal approach
- * one field of a struct by replacing it with another value. The normal approach
+/// doesn't always work:
- * doesn't always work:
+///
- *
+/// ```rust,ignore
- * ```rust,ignore
+/// struct Buffer<T> { buf: Vec<T> }
- * struct Buffer<T> { buf: Vec<T> }
+///
- *
+/// impl<T> Buffer<T> {
- * impl<T> Buffer<T> {
+///     fn get_and_reset(&mut self) -> Vec<T> {
- *     fn get_and_reset(&mut self) -> Vec<T> {
+///         // error: cannot move out of dereference of `&mut`-pointer
- *         // error: cannot move out of dereference of `&mut`-pointer
+///         let buf = self.buf;
- *         let buf = self.buf;
+///         self.buf = Vec::new();
- *         self.buf = Vec::new();
+///         buf
- *         buf
+///     }
- *     }
+/// }
- * }
+/// ```
- * ```
+///
- *
+/// Note that `T` does not necessarily implement `Clone`, so it can't even
- * Note that `T` does not necessarily implement `Clone`, so it can't even
+/// clone and reset `self.buf`. But `replace` can be used to disassociate
- * clone and reset `self.buf`. But `replace` can be used to disassociate
+/// the original value of `self.buf` from `self`, allowing it to be returned:
- * the original value of `self.buf` from `self`, allowing it to be returned:
+///
- *
+/// ```rust
- * ```rust
+/// # struct Buffer<T> { buf: Vec<T> }
- * # struct Buffer<T> { buf: Vec<T> }
+/// impl<T> Buffer<T> {
- * impl<T> Buffer<T> {
+///     fn get_and_reset(&mut self) -> Vec<T> {
- *     fn get_and_reset(&mut self) -> Vec<T> {
+///         use std::mem::replace;
- *         use std::mem::replace;
+///         replace(&mut self.buf, Vec::new())
- *         replace(&mut self.buf, Vec::new())
+///     }
- *     }
+/// }
- * }
+/// ```
- * ```
- */
 #[inline]
 #[stable]
 pub fn replace<T>(dest: &mut T, mut src: T) -> T {