Design by contract in C++

Since I were tought about Bertrand Meyer’s Eiffel and its nice feature of design by contract I got interested in validation and verification of systems. Since most of the code I write is in C, C++ or even Java, I have looked for elegant ways of including contracts in C & C++. Next is what I am going to use in next developments.
Design by Contract in C++
The document is written by the author of “Imperfect C++”: Imperfect C++