Hello all, I have released Contract++ 0.4.0 on SourceForge. If ever accepted into Boost, this library will be Boost.Contract (and all macros/symbols will be prefixed by BOOST_/boost::). This library implements Contract Programming for the C++ programming language (see the end of this email). In addition, the library implements virtual specifiers (final, override, and new, see C++11), concept checking, and named parameters. This library is implemented for the C++03 standard and it does not require C++11. Documentation: http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp_... Source: http://sourceforge.net/projects/contractpp/files/latest/download I would like to request a formal Boost review of the library. Comments are welcome! Thanks, --Lorenzo INTRODUCTION Contract Programming is also known as Design by Contract(TM) and it was first introduced by the Eiffel programming language. All Contract Programming features of the Eiffel programming language are supported by this library, among others: * Support for preconditions, postconditions, class invariants, block invariants, and loop variants. * Subcontract derived classes (with support for pure virtual functions and multiple inheritance). * Access expression old values and function return value in postconditions. * Optional compilation and checking of preconditions, postconditions, class invariants, block invariants, and loop variants. * Customizable actions on contract assertion failure (terminate by default but it can throw, exit, etc). All features: http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp_... EXAMPLE The example below shows how to use this library to program contracts for the STL member function std::vector::push_back (in order to illustrate subcontracting, the vector class inherits from the somewhat arbitrary pushable base class). #include <contract.hpp> // This library. #include <boost/concept_check.hpp> #include <vector> #include "pushable.hpp" // Some base class. CONTRACT_CLASS( template( typename T ) requires( boost::CopyConstructible<T> ) // Concepts. class (vector) extends( public pushable<T> ) // Subcontracting. ) { CONTRACT_CLASS_INVARIANT_TPL( empty() == (size() == 0) // More class invariants here... ) public: typedef typename std::vector<T>::size_type size_type; public: typedef typename std::vector<T>::const_reference const_reference; CONTRACT_FUNCTION_TPL( public void (push_back) ( (T const&) value ) override precondition( size() < max_size() // More preconditions here... ) postcondition( auto old_size = CONTRACT_OLDOF size(), // Old-of values. size() == old_size + 1 // More postconditions here... ) ) { vector_.push_back(value); // Original function body. } // Rest of class here (possibly with more contracts)... public: bool empty ( void ) const { return vector_.empty(); } public: size_type size ( void ) const { return vector_.size(); } public: size_type max_size ( void ) const { return vector_.max_size(); } public: const_reference back ( void ) const { return vector_.back(); } private: std::vector<T> vector_; }; NOTES This library suffers of two limitations: 1. The unusual syntax used to declare classes and functions within the macros which causes cryptic compiler errors when not used correctly (syntax error checking and reporting could be somewhat improved in future revisions of the library but there are fundamental limitations on what can be done using the preprocessor). http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp_... 2. High compilation times (the authors have not tried to optimize the library proprocessor and template meta-programming code yet, that will be the focus of future releases). http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp_... This library could be extended to also support concept definitions (at least for C++11): http://contractpp.svn.sourceforge.net/viewvc/contractpp/releases/contractpp_...