1 files changed, 83 insertions, 0 deletions
diff --git a/third_party/rust/clap_builder/src/output/fmt.rs b/third_party/rust/clap_builder/src/output/fmt.rs
new file mode 100644
index 0000000000..0c9a24f33a
--- /dev/null
+++ b/third_party/rust/clap_builder/src/output/fmt.rs
@@ -0,0 +1,83 @@
+use crate::builder::StyledStr;
+use crate::util::color::ColorChoice;
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub(crate) enum Stream {
+    Stdout,
+    Stderr,
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct Colorizer {
+    stream: Stream,
+    #[allow(unused)]
+    color_when: ColorChoice,
+    content: StyledStr,
+}
+
+impl Colorizer {
+    pub(crate) fn new(stream: Stream, color_when: ColorChoice) -> Self {
+        Colorizer {
+            stream,
+            color_when,
+            content: Default::default(),
+        }
+    }
+
+    pub(crate) fn with_content(mut self, content: StyledStr) -> Self {
+        self.content = content;
+        self
+    }
+}
+
+/// Printing methods.
+impl Colorizer {
+    #[cfg(feature = "color")]
+    pub(crate) fn print(&self) -> std::io::Result<()> {
+        let color_when = match self.color_when {
+            ColorChoice::Always => anstream::ColorChoice::Always,
+            ColorChoice::Auto => anstream::ColorChoice::Auto,
+            ColorChoice::Never => anstream::ColorChoice::Never,
+        };
+
+        let mut stdout;
+        let mut stderr;
+        let writer: &mut dyn std::io::Write = match self.stream {
+            Stream::Stderr => {
+                stderr = anstream::AutoStream::new(std::io::stderr().lock(), color_when);
+                &mut stderr
+            }
+            Stream::Stdout => {
+                stdout = anstream::AutoStream::new(std::io::stdout().lock(), color_when);
+                &mut stdout
+            }
+        };
+
+        self.content.write_to(writer)
+    }
+
+    #[cfg(not(feature = "color"))]
+    pub(crate) fn print(&self) -> std::io::Result<()> {
+        // [e]println can't be used here because it panics
+        // if something went wrong. We don't want that.
+        match self.stream {
+            Stream::Stdout => {
+                let stdout = std::io::stdout();
+                let mut stdout = stdout.lock();
+                self.content.write_to(&mut stdout)
+            }
+            Stream::Stderr => {
+                let stderr = std::io::stderr();
+                let mut stderr = stderr.lock();
+                self.content.write_to(&mut stderr)
+            }
+        }
+    }
+}
+
+/// Color-unaware printing. Never uses coloring.
+impl std::fmt::Display for Colorizer {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.content.fmt(f)
+    }
+}