New anti-pattern: deny warnings

Author: llogiq

README.md

@@ -57,7 +57,7 @@ language.
 * TODO wildcard matches
 * TODO taking an enum rather than having multiple functions
 * TODO `unwrap()`ing every `Result` instead of forwarding it
-
+* [`#![deny(warnings)]`}}(anti_patterns/deny-warnings.md)
 
 
 ## Contributing

anti_patterns/deny-warnings.md

@@ -0,0 +1,35 @@
+# `#![deny(warnings)]`
+
+## Description
+
+A well-intentioned crate author wants to ensure their code builds without
+warnings. So they annotate their crate root with
+
+## Example
+
+```rust
+#![deny(warnings)]
+
+// All is well.
+```
+
+## Drawbacks
+
+Until, say, the language changes, and as part of the transition, a lint is
+introduced that `warn`s, and Boom! The code no longer builds. Or someone tries
+to compile the code with additional lints (e.g. [clippy]), only to find out
+that they have to remove the annotation first.
+
+## Alternatives
+
+Our plucky developer hero should have used
+`RUSTFLAGS="-D warnings" cargo build"` to build their crate, removing
+the need for the annotation in their code.
+
+## See also
+
+- Type `rustc -W help` for a list of lints on your system. Also type
+`rustc --help` for a general list of options
+- [clippy] is a collection of lints for better Rust code
+
+[clippy]: https://github.com/Manishearth/rust-clippy