Switch with strings [C++]

switchStrings.cpp

#include <iostream>
#include <map>
#include <vector>

using namespace std;

void setupSwitchWithStrings(vector<string> strings, string& value, map<string,uint16_t>& map);
void toLower(string& str);
	
int main() {
	
	map<string,uint16_t> mappedString;
	string value;
	
	getline(cin,value);

	setupSwitchWithStrings({"Bye", "Hi", "John", "How are you?"}, value, mappedString);
	enum { bye, hi, john, howAreYou };
	
	switch (mappedString[value]) {
		
		case bye:
			cout << "Have a great day!" << endl;
			break;
			
		case hi:
			cout << "Hello!!" << endl;
			break;
			
		case john:
			cout << "Nice to meet you!" << endl;
			break;
			
		case howAreYou:
			cout << "I'm fine!" << endl;
			break;
			
		default:
			cout << "?" << endl;
			break;
	}
	
	return 0;
}

void setupSwitchWithStrings(vector<string> strings, string& value, map<string,uint16_t>& map) {
	
	uint16_t idx = 0;
	
	for (string& str: strings) {
		toLower(str);
		map[str] = idx;
		++idx;
	}
	
	toLower(value);
}

void toLower(string& str) {
	transform(str.begin(), str.end(), str.begin(), ::tolower);
}