Added README

Author: mzabaluev

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Mikhail Zabaluev <mikhail.zabaluev@gmail.com>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"
+readme = "README.md"
 
 [features]
 default = []

README.md

@@ -0,0 +1,31 @@
+# Unwrapping Results With Compile-Time Guarantee of Infallibility
+
+The Rust standard type `Result` sometimes occurs parameterized
+with an error type that has no possible values, such as
+`std::convert::Infallible`. Consequently, calling the `unwrap` method on a
+`Result` value of such a type will never panic.
+Therein lies a maintainability hazard: if the error parameter type is later
+changed to one that can represent actually occurring errors, those uses of
+`unwrap` that could previously be relied upon to be infallible, quietly
+become liable to panic.
+
+To help prevent this from happening without a compile-time safeguard,
+this crate provides an alternative method `unwrap_infallible` that shall only
+be available for `Result` values with a known-impossible `Err` variant.
+
+## License
+
+Licensed under either of
+
+ * Apache License, Version 2.0
+   ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license
+   ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+## Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.