> Discrete Optimization > Rates: Using Semi-Continuous Variables > What Is IloCplex? > IloCplex and Extraction

As an ILOG Concert algorithm, an instance of IloCplex extracts the following classes from a model when you call its method IloCplex::extract:

There are also facilities in IloCplex for representing piecewise-linear functions, as explained in Transport: Piecewise Linear Optimization, and logical constraints, introduced in Logical Constraints in Optimization. As that chapter explains, logical constraints in ILOG CPLEX are available only to C++ users.