Mathematical Expression Parser and Evaluator

We need to parse and evaluate generic mathematical expressions like below: std::string input = "(XT2 > XT1*XT3 + 21 || XT3 > 31) && (XT4 > 41 || (XT5 < 51 && XT6 > 61))"; XTs are the name of variables we have. They are _not_ primitive int, double etc. They are from a mathematical library that support the following functions: add (XT x1, XT x2) {//this will do x1+x2} multiply (XT x1, XT x2) {//this will do x1*x2} boolean_and (XT x1, XT x2) {//this will do x1 && x2} ... Here is an example: [login to view URL] = 10; [login to view URL] = 20; std::string input = "(X1 * X2 > 35) && ( X2 < 100 ) "; XT_boolean XT_result = xt_parse_evaluate (input); std::cout 35 will return false) You can use standard C++ and boost library for the implementation.