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+<div align="center">
+
+  <h1><code>Arbitrary</code></h1>
+
+  <p><strong>The trait for generating structured data from arbitrary, unstructured input.</strong></p>
+
+  <img alt="GitHub Actions Status" src="https://github.com/rust-fuzz/rust_arbitrary/workflows/Rust/badge.svg"/>
+
+</div>
+
+## About
+
+The `Arbitrary` crate lets you construct arbitrary instances of a type.
+
+This crate is primarily intended to be combined with a fuzzer like [libFuzzer
+and `cargo-fuzz`](https://github.com/rust-fuzz/cargo-fuzz) or
+[AFL](https://github.com/rust-fuzz/afl.rs), and to help you turn the raw,
+untyped byte buffers that they produce into well-typed, valid, structured
+values. This allows you to combine structure-aware test case generation with
+coverage-guided, mutation-based fuzzers.
+
+## Documentation
+
+[**Read the API documentation on `docs.rs`!**](https://docs.rs/arbitrary)
+
+## Example
+
+Say you're writing a color conversion library, and you have an `Rgb` struct to
+represent RGB colors. You might want to implement `Arbitrary` for `Rgb` so that
+you could take arbitrary `Rgb` instances in a test function that asserts some
+property (for example, asserting that RGB converted to HSL and converted back to
+RGB always ends up exactly where we started).
+
+### Automatically Deriving `Arbitrary`
+
+Automatically deriving the `Arbitrary` trait is the recommended way to implement
+`Arbitrary` for your types.
+
+Automatically deriving `Arbitrary` requires you to enable the `"derive"` cargo
+feature:
+
+```toml
+# Cargo.toml
+
+[dependencies]
+arbitrary = { version = "1", features = ["derive"] }
+```
+
+And then you can simply add `#[derive(Arbitrary)]` annotations to your types:
+
+```rust
+// rgb.rs
+
+use arbitrary::Arbitrary;
+
+#[derive(Arbitrary)]
+pub struct Rgb {
+    pub r: u8,
+    pub g: u8,
+    pub b: u8,
+}
+```
+
+#### Customizing single fields
+
+This can be particular handy if your structure uses a type that does not implement `Arbitrary` or you want to have more customization for particular fields.
+
+```rust
+#[derive(Arbitrary)]
+pub struct Rgba {
+    // set `r` to Default::default()
+    #[arbitrary(default)]
+    pub r: u8,
+
+    // set `g` to 255
+    #[arbitrary(value = 255)]
+    pub g: u8,
+
+    // Generate `b` with a custom function of type
+    //
+    //    fn(&mut Unstructured) -> arbitrary::Result<T>
+    //
+    // where `T` is the field's type.
+    #[arbitrary(with = arbitrary_b)]
+    pub b: u8,
+
+    // Generate `a` with a custom closure (shortuct to avoid a custom funciton)
+    #[arbitrary(with = |u: &mut Unstructured| u.int_in_range(0..=64))]
+    pub a: u8,
+}
+
+fn arbitrary_b(u: &mut Unstructured) -> arbitrary::Result<u8> {
+    u.int_in_range(64..=128)
+}
+```
+
+### Implementing `Arbitrary` By Hand
+
+Alternatively, you can write an `Arbitrary` implementation by hand:
+
+```rust
+// rgb.rs
+
+use arbitrary::{Arbitrary, Result, Unstructured};
+
+#[derive(Copy, Clone, Debug)]
+pub struct Rgb {
+    pub r: u8,
+    pub g: u8,
+    pub b: u8,
+}
+
+impl<'a> Arbitrary<'a> for Rgb {
+    fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self> {
+        let r = u8::arbitrary(u)?;
+        let g = u8::arbitrary(u)?;
+        let b = u8::arbitrary(u)?;
+        Ok(Rgb { r, g, b })
+    }
+}
+```
+
+## License
+
+Licensed under dual MIT or Apache-2.0 at your choice.
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in this project by you, as defined in the Apache-2.0 license,
+shall be dual licensed as above, without any additional terms or conditions.