https://issues.dlang.org/show_bug.cgi?id=24210

          Issue ID: 24210
           Summary: Function types are not documented
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dlang.org
          Assignee: nobody@puremagic.com
          Reporter: nick@geany.org

There is no explanation of what they are used for.

PR incoming.

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