I suppose my intent here was to enforce "purity" with an immutable ptr... eg. the caller couldn't do something ridiculous like:
```
const char facepalm[30] = "value out of sync\0";
const char *result = RvalContainerPrimitiveAsString(...);
result = &facepalm;
```

Chances of something like the above happening...? Slim. Chances of not getting caught in a review...? I'd hope even slimmer :)

IDK, this function just _felt_ pure to me... give the word again and I'll glady change it.