Having done a few years of cross-mobile C++, we get into opinion territory perhaps, but it was never a smooth experience for me. Apologies, but don't have time

Having done a few years of cross-mobile C++, we get into opinion territory perhaps, but it was never a smooth experience for me. Apologies, but don't have time today to go into too much justification for my opinion. It can be the lesser evil (e.g. you have an existing greater-than 10K LoC C++ codebase that you don't feel like porting to both Java and Swift), but, let's say I want to write a few methods, a few hundred lines of business logic, to validate user input on all three platforms. Sure I can bring out the C++ hammer but I've found that decision comes with more tool-fatigue overhead than it's worth, especially on Android. And I don't know the C++->Javascript story that well, that may be smoothing out these days. But even if all that worked smoothly, what if I want to move my logic to PHP as well? I know, now I'm getting crazy, but that's what the poster asked for :)