Index: Cargo.toml
==================================================================
--- Cargo.toml
+++ Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "bmap"
-version = "0.2.0"
+version = "0.2.1"
 edition = "2021"
 license = "0BSD"
 # https://crates.io/category_slugs
 categories = [ "data-structures" ]
 keywords = [ "bitmap", "bitvec" ]

Index: src/lib.rs
==================================================================
--- src/lib.rs
+++ src/lib.rs
@@ -1,7 +1,9 @@
 //! Container of bits adressable by an index.
 
+use std::fmt;
+
 pub mod err;
 
 pub use err::Error;
 
 /// Number of bits per slot in the bits vector.
@@ -17,10 +19,31 @@
 
   /// Number of remaining bits.  This is functionally equivalent to "total
   /// number of zeroes in the container".
   remain: usize
 }
+
+impl fmt::Debug for CountedBitmap {
+  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    let blocks: Vec<String> = self
+      .iter_ones_block()
+      .map(|(first, last)| {
+        if first != last {
+          format!("{}-{}", first, last)
+        } else {
+          format!("{}", first)
+        }
+      })
+      .collect();
+    let set_blocks = blocks.join(",");
+    write!(
+      f,
+      "BMap {{ length: {}, remain: {}, [{}] }}",
+      self.length, self.remain, set_blocks
+    )
+  }
+}
 
 
 impl CountedBitmap {
   /// Create a new bit vector which can hold `bitcount` number of bits.
   ///
@@ -550,8 +573,45 @@
     let mut bmap = CountedBitmap::new(1);
     assert!(!bmap.is_finished());
     bmap.set(0).unwrap();
     assert!(bmap.is_finished());
   }
+
+  #[test]
+  fn dbg_output0() {
+    let bmap = CountedBitmap::new(3);
+    let s = format!("{:?}", bmap);
+    assert_eq!(s, "BMap { length: 3, remain: 3, [] }");
+  }
+
+  #[test]
+  fn dbg_output1() {
+    let mut bmap = CountedBitmap::new(3);
+    bmap.set(1).unwrap();
+    let s = format!("{:?}", bmap);
+    assert_eq!(s, "BMap { length: 3, remain: 2, [1] }");
+  }
+
+  #[test]
+  fn dbg_output2() {
+    let mut bmap = CountedBitmap::new(5);
+    bmap.set(1).unwrap();
+    bmap.set(2).unwrap();
+    let s = format!("{:?}", bmap);
+    assert_eq!(s, "BMap { length: 5, remain: 3, [1-2] }");
+  }
+
+  #[test]
+  fn dbg_output3() {
+    let mut bmap = CountedBitmap::new(7);
+    bmap.set(1).unwrap();
+    bmap.set(2).unwrap();
+
+    bmap.set(4).unwrap();
+    bmap.set(5).unwrap();
+
+    let s = format!("{:?}", bmap);
+    assert_eq!(s, "BMap { length: 7, remain: 3, [1-2,4-5] }");
+  }
 }
 
 // vim: set ft=rust et sw=2 ts=2 sts=2 cinoptions=2 tw=79 :

Index: www/changelog.md
==================================================================
--- www/changelog.md
+++ www/changelog.md
@@ -2,23 +2,43 @@
 
 ⚠️  indicates a breaking change.
 
 ## [Unreleased]
 
-[Details](/vdiff?from=bmap-0.1.0&to=trunk)
+[Details](/vdiff?from=bmap-0.2.1&to=trunk)
+
+### Added
+
+### Changed
+
+### Removed
+
+---
+
+## [0.2.1] - 2024-03-21
+
+[Details](/vdiff?from=bmap-0.2.0&to=bmap-0.2.1)
+
+### Changed
+
+- Implement `Debug` for `CountedBitmap`.
+
+---
+
+## [0.2.0] - 2024-03-21
+
+[Details](/vdiff?from=bmap-0.1.0&to=bmap-0.2.0)
 
 ### Added
 
 - `CountedBitmap::is_empty()` returns `true` is no bits have been set in the
-  bit map. 
+  bit map.
 
 ### Changed
 
 - ⚠️ `CountedBitmap::new()` made infallible.
 
-### Removed
-
 ---
 
 ## [0.1.0]
 
 Initial release.