Also, remove the other brackets, because they make the whole sentence look awkward.
There are two kinds of configuration options, one that is either defined or not
(`#[cfg(foo)]`), and the other that contains a string that can be checked
-against (`#[cfg(bar = "baz")]` (currently only compiler-defined configuration
-options can have the latter form).
+against (`#[cfg(bar = "baz")]`). Currently, only compiler-defined configuration
+options can have the latter form.
```
// The function is only included in the build when compiling for OSX