Not many folks use the macros that those macro-trait packages define, but the technique itself is in widespread use throughout the core language and standard li

Not many folks use the macros that those macro-trait packages define, but the technique itself is in widespread use throughout the core language and standard library. That's where it was first posited and implemented, in fact: https://github.com/JuliaLang/julia/pull/8432 https://github.com/JuliaLang/julia/pull/8432 (and see the link to the "trait trick")