Thanks, that context is helpful, particularly the motivating example of test variants. I worked on a Java library which also tackles the test variants problem:

Thanks, that context is helpful, particularly the motivating example of test variants. I worked on a Java library which also tackles the test variants problem: https://github.com/square/burst https://github.com/square/burst With this library you would write something like enum Box { BOX1, BOX2, BOX3, BOX4 } enum Compiler { GCC, CLANG, MSVC } @Test void loadtest(Box box, Compiler compiler) { ... } I'm not sure if there are any big uses for cartesian products outside of test variants though. Probably not enough to justify making it a first-class language feature.