Rollup merge of rust-lang#35279 - cengizIO:master, r=brson

Provide a cleaner documentation for 'write!'

Hello!

This is my attempt to fix rust-lang#35110

Any feedback is more than welcome!

Cheers!

src/libcore/macros.rs

@@ -229,14 +229,28 @@ macro_rules! try {
     })
 }
 
-/// Use the `format!` syntax to write data into a buffer.
+/// Write formatted data into a buffer
 ///
-/// This macro is typically used with a buffer of `&mut `[`Write`][write].
+/// This macro accepts any value with `write_fmt` method as a writer, a format string, and a list
+/// of arguments to format.
+///
+/// `write_fmt` method usually comes from an implementation of [`std::fmt::Write`][fmt_write] or
+/// [`std::io::Write`][io_write] traits. These are sometimes called 'writers'.
+///
+/// Passed arguments will be formatted according to the specified format string and the resulting
+/// string will be passed to the writer.
 ///
 /// See [`std::fmt`][fmt] for more information on format syntax.
 ///
+/// Return value is completely dependent on the 'write_fmt' method.
+///
+/// Common return values are: [`Result`][enum_result], [`io::Result`][type_result]
+///
 /// [fmt]: ../std/fmt/index.html
-/// [write]: ../std/io/trait.Write.html
+/// [fmt_write]: ../std/fmt/trait.Write.html
+/// [io_write]: ../std/io/trait.Write.html
+/// [enum_result]: ../std/result/enum.Result.html
+/// [type_result]: ../std/io/type.Result.html
 ///
 /// # Examples
 ///
@@ -255,16 +269,31 @@ macro_rules! write {
     ($dst:expr, $($arg:tt)*) => ($dst.write_fmt(format_args!($($arg)*)))
 }
 
-/// Use the `format!` syntax to write data into a buffer, appending a newline.
-/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`)
-/// alone (no additional CARRIAGE RETURN (`\r`/`U+000D`).
+/// Write formatted data into a buffer, with appending a newline.
+///
+/// On all platforms, the newline is the LINE FEED character (`\n`/`U+000A`) alone
+/// (no additional CARRIAGE RETURN (`\r`/`U+000D`).
 ///
-/// This macro is typically used with a buffer of `&mut `[`Write`][write].
+/// This macro accepts any value with `write_fmt` method as a writer, a format string, and a list
+/// of arguments to format.
+///
+/// `write_fmt` method usually comes from an implementation of [`std::fmt::Write`][fmt_write] or
+/// [`std::io::Write`][io_write] traits. These are sometimes called 'writers'.
+///
+/// Passed arguments will be formatted according to the specified format string and the resulting
+/// string will be passed to the writer.
 ///
 /// See [`std::fmt`][fmt] for more information on format syntax.
 ///
+/// Return value is completely dependent on the 'write_fmt' method.
+///
+/// Common return values are: [`Result`][enum_result], [`io::Result`][type_result]
+///
 /// [fmt]: ../std/fmt/index.html
-/// [write]: ../std/io/trait.Write.html
+/// [fmt_write]: ../std/fmt/trait.Write.html
+/// [io_write]: ../std/io/trait.Write.html
+/// [enum_result]: ../std/result/enum.Result.html
+/// [type_result]: ../std/io/type.Result.html
 ///
 /// # Examples
 ///