Vec is a template class mainly for numerical vectors. We can define any type of vector and the number of components:

Vec<double,19> myVector; 

We can also use any of the predefined types:

typedef Vec<uchar, 2> Vec2b; 
typedef Vec<uchar, 3> Vec3b; 
typedef Vec<uchar, 4> Vec4b; 
 
typedef Vec<short, 2> Vec2s; 
typedef Vec<short, 3> Vec3s; 
typedef Vec<short, 4> Vec4s; 
 
typedef Vec<int, 2> Vec2i; 
typedef Vec<int, 3> Vec3i; 
typedef Vec<int, 4> Vec4i; 
 
typedef Vec<float, 2> Vec2f; 
typedef Vec<float, 3> Vec3f; 
typedef Vec<float, 4> Vec4f; 
typedef Vec<float, 6> Vec6f; 
 
typedef Vec<double, 2> Vec2d; 
typedef Vec<double, 3> Vec3d; 
typedef Vec<double, 4> Vec4d; 
typedef Vec<double, 6> Vec6d;