1 files changed, 49 insertions, 0 deletions
diff --git a/examples/fmt.rs b/examples/fmt.rs
new file mode 100644
index 0000000..3bb9b8c
--- /dev/null
+++ b/examples/fmt.rs
@@ -0,0 +1,49 @@
+//! An example of implementing Rust's standard formatting and parsing traits for flags types.
+
+use core::{fmt, str};
+
+fn main() -> Result<(), bitflags::parser::ParseError> {
+    bitflags::bitflags! {
+        // You can `#[derive]` the `Debug` trait, but implementing it manually
+        // can produce output like `A | B` instead of `Flags(A | B)`.
+        // #[derive(Debug)]
+        #[derive(PartialEq, Eq)]
+        pub struct Flags: u32 {
+            const A = 1;
+            const B = 2;
+            const C = 4;
+            const D = 8;
+        }
+    }
+
+    impl fmt::Debug for Flags {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            fmt::Debug::fmt(&self.0, f)
+        }
+    }
+
+    impl fmt::Display for Flags {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            fmt::Display::fmt(&self.0, f)
+        }
+    }
+
+    impl str::FromStr for Flags {
+        type Err = bitflags::parser::ParseError;
+
+        fn from_str(flags: &str) -> Result<Self, Self::Err> {
+            Ok(Self(flags.parse()?))
+        }
+    }
+
+    let flags = Flags::A | Flags::B;
+
+    println!("{}", flags);
+
+    let formatted = flags.to_string();
+    let parsed: Flags = formatted.parse()?;
+
+    assert_eq!(flags, parsed);
+
+    Ok(())
+}