A std::vector can be initialized in several ways while declaring it:
C++11
std::vector<int> v{ 1, 2, 3 }; // v becomes {1, 2, 3}
// Different from std::vector<int> v(3, 6)
std::vector<int> v{ 3, 6 }; // v becomes {3, 6}
// Different from std::vector<int> v{3, ...
