In fact it's really mostly name space management. Python doesn't require you to pull in "upper" because it starts with a relatively big name space. It doesn't require you declare the main program because you're relying on the fact that Python executes a file on loading it (and that reliance is arguably bad Python style). All of the "std::" stuff is a name space management choice.
... and the rest has nothing to do with static typing either. The way the code is indented on multiple lines is a stylistic convention. The transform primitive requiring you to specify bounds is a library choice, related to the language's apparent lack of a universal way to map over a container. I'm not sure why you need the lambda. The rewrite in place is memory model stuff inherited from C.
In Haskell, which is fully compiled and is about the most rigid static typed language you could ever imagine:
import Data.Char(toUpper)
main = putStrLn (toUpper <$> "hello")
std::string ToUpper(const std::string& str) {
std::string as_lower(str);
absl::c_transform(str, as_lower, std::toupper);
return as_lower;
}
int main() {
std::cout << ToUpper("hello");
return 0;
}