The quality of the translation results of Delphi code to C++ with Delphi2Cpp is guaranteed by a collection of test files. The test cases mostly are modified examples from Embarcadero and from Delphi Basics:
The output operations in the examples were replaced by boolean expressions which can be checked at the execution of the tests. The modified files then were inserted into a DUnit application. (DUnit is a testing framework which is integrated into the RAD Studio.)
After verification that the tests are working correctly in Delphi, the code is translated with Delphi2Cpp to C++. The translated test files then are inserted into a C++ test application (C++-Builder or Visual C++ respectively). There the tests are repeated then in C++.
The examples below are only a small selection of the whole test suite, which comprises more than a hundred of such test files.