Rollup merge of rust-lang#124992 - foresterre:example/is-terminal, r=ChrisDenton

Add example to IsTerminal::is_terminal

Author: matthiaskrgr

Diff for: std/src/io/stdio.rs

@@ -1161,7 +1161,41 @@ pub trait IsTerminal: crate::sealed::Sealed {
     /// starting with `msys-` or `cygwin-` and ending in `-pty` will be considered terminals.
     /// Note that this [may change in the future][changes].
     ///
+    /// # Examples
+    ///
+    /// An example of a type for which `IsTerminal` is implemented is [`Stdin`]:
+    ///
+    /// ```no_run
+    /// use std::io::{self, IsTerminal, Write};
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let stdin = io::stdin();
+    ///
+    ///     // Indicate that the user is prompted for input, if this is a terminal.
+    ///     if stdin.is_terminal() {
+    ///         print!("> ");
+    ///         io::stdout().flush()?;
+    ///     }
+    ///
+    ///     let mut name = String::new();
+    ///     let _ = stdin.read_line(&mut name)?;
+    ///
+    ///     println!("Hello {}", name.trim_end());
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// The example can be run in two ways:
+    ///
+    /// - If you run this example by piping some text to it, e.g. `echo "foo" | path/to/executable`
+    ///   it will print: `Hello foo`.
+    /// - If you instead run the example interactively by running the executable directly, it will
+    ///   panic with the message "Expected input to be piped to the process".
+    ///
+    ///
     /// [changes]: io#platform-specific-behavior
+    /// [`Stdin`]: crate::io::Stdin
     #[stable(feature = "is_terminal", since = "1.70.0")]
     fn is_terminal(&self) -> bool;
 }