Constructs B-splines and its integral, M-splines and its integral (I-splines), convex splines (C-splines), generalized Bernstein polynomials, and their derivatives. It also contains a C++ head-only library integrated with Rcpp. See De Boor (1978) <doi:10.1002/zamm.19800600129>, Ramsay (1988) <doi:10.1214/ss/1177012761>, and Meyer (2008) <doi:10.1214/08-AOAS167> for more information about the spline basis.