Using variadic templates with lambda expressions in C++ for constrained optimization

Constrained optimization problems are encountered in numerous domains, such as protein folding, Magnetic Resonance Image reconstruction, and radiation therapy. In this problem, we are given with an objective function which is to be minimized or maximized with respect to constraints on some variables. The constraints can either be soft constraints or hard constraints, which can be specified by boolean operators, such as equality, relational, and conditional operators.

This post provides insight on how to model constraints using lambda expressions, and how to pass a varying number of constraints to a function using variadic templates. Before moving on with the C++ implementation, it will be helpful to review how variadic functions are used in C and how they differ from the …