1 files changed, 54 insertions, 0 deletions
diff --git a/vendor/powerfmt/src/ext.rs b/vendor/powerfmt/src/ext.rs
new file mode 100644
index 0000000..20af7c0
--- /dev/null
+++ b/vendor/powerfmt/src/ext.rs
@@ -0,0 +1,54 @@
+//! Extension traits.
+
+use core::fmt::{Alignment, Arguments, Formatter, Result, Write};
+
+mod sealed {
+    pub trait Sealed {}
+
+    impl Sealed for core::fmt::Formatter<'_> {}
+}
+
+/// An extension trait for [`core::fmt::Formatter`].
+pub trait FormatterExt: sealed::Sealed {
+    /// Writes the given arguments to the formatter, padding them with the given width. If `width`
+    /// is incorrect, the resulting output will not be the requested width.
+    fn pad_with_width(&mut self, width: usize, args: Arguments<'_>) -> Result;
+}
+
+impl FormatterExt for Formatter<'_> {
+    fn pad_with_width(&mut self, args_width: usize, args: Arguments<'_>) -> Result {
+        let Some(final_width) = self.width() else {
+            // The caller has not requested a width. Write the arguments as-is.
+            return self.write_fmt(args);
+        };
+        let Some(fill_width @ 1..) = final_width.checked_sub(args_width) else {
+            // No padding will be present. Write the arguments as-is.
+            return self.write_fmt(args);
+        };
+
+        let alignment = self.align().unwrap_or(Alignment::Left);
+        let fill = self.fill();
+
+        let left_fill_width = match alignment {
+            Alignment::Left => 0,
+            Alignment::Right => fill_width,
+            Alignment::Center => fill_width / 2,
+        };
+        let right_fill_width = match alignment {
+            Alignment::Left => fill_width,
+            Alignment::Right => 0,
+            // When the fill is not even on both sides, the extra fill goes on the right.
+            Alignment::Center => (fill_width + 1) / 2,
+        };
+
+        for _ in 0..left_fill_width {
+            self.write_char(fill)?;
+        }
+        self.write_fmt(args)?;
+        for _ in 0..right_fill_width {
+            self.write_char(fill)?;
+        }
+
+        Ok(())
+    }
+}