What have you done with UDAs?

[Kapps via Digitalmars-d]

On Monday, 22 June 2015 at 19:09:40 UTC, weaselcat wrote:
> I never seem to use them for anything, has anyone else done 
> anything interesting with them?

Like several others, I use them for generating command line 
interfaces to set variables / invoke methods using reflection. 
For example 
https://shardsoft.com/stash/projects/SHARD/repos/dap/browse/source/dap/Standalone.d#51 results in something like:

D Asset Pipeline
Converts assets into an intermediate post-processed format more 
efficiently loaded at runtime.
Commands:
	[--init]: Initializes the folder structure for a dap repository 
using a Content subdirectory in this folder.
	[--clean]: Cleans the output directory, removing all built 
assets.
	[-h|--help]: Displays the help string.
	[-a|--add]: Adds the given raw asset to the asset store using 
the default processor and default settings.
	[-r|--remove]: Removes the asset with the specified qualified 
name from the asset store.
	[-l|--list]: Lists all assets currently stored.
	[-b|--build]: Builds all dirty assets using current settings.
	[-i|--inspect]: Shows all properties of the given asset.
	[-o|--open]: Opens the given asset in an external editor.
	[-m|--modify]: Modifies a property of a processor on an asset, 
or the processor used to build the asset.
Options:
	[--input-folder]: The folder that assets should be read from and 
settings stored in. Default: Content/Input
	[--output-folder]: The folder that generated assets should be 
saved to. Default: Content/Output
	[--log-level]: The minimum severity for a message to be logged. 
Default: info