In the C++ API of Concert Technology, the class IloEnv initializes output streams for general information, for error messages, and for warnings. The class IloAlgorithm supports these communication streams, and the class IloCplex inherits its methods. For general output, there is the method IloAlgorithm::out. For warnings and nonfatal conditions, there is the method IloAlgorithm::warning. For errors, there is the method IloAlgorithm::error.

By default, an instance of IloEnv defines the output stream referenced by the method out as the system cout in the C++ API, but you can use the method setOut to redefine it as you prefer. For example, to suppress output to the screen in a C++ application, use this method with this argument:

setOut(IloEnv::getNullStream)

Likewise, you can use the methods IloAlgorithm::setWarning and setError to redefine those channels as you prefer.