array search c++

#include <iostream>
2 #include <array>
3 #include <string>
4 #include <algorithm>
5
6 using namespace std;
7
8 int main(){
9 array<string, 4> colours = {"blue", "black", "red", "green"};
10 sort(colours.begin(), colours.end()); //must be sorted
11 string key = "black";
12 //look for black
13 bool found = binary_search(colours.begin(), colours.end(), key);
14 if (found){
15 cout << "We found the key 'black'" << endl;
16 }
17 return 0;
18 }