100 // Joins a container of things into a single string, using the given separator.
102 std::string Join(ContainerT&& things, SeparatorT separator) {  in Join()  argument
105   if (things.empty()) {  in Join()
107   } else if (things.size() == 1) {  in Join()
112       return *things.begin();  in Join()
116       return std::string(*things.begin());  in Join()
133         std::next(things.begin()), things.end(), std::string_view(*things.begin()).size(),  in Join()
141     result.append(*things.begin());  in Join()
142     for(auto it = std::next(things.begin()); it != things.end(); ++it) {  in Join()
153     result << *things.begin();  in Join()
154     for (auto it = std::next(things.begin()); it != things.end(); ++it) {  in Join()