#include #include using namespace std; #define EVAL(expr) (Catch().append(#expr "\n") < expr).str() class Catch{ ostringstream oss; bool first; public: Catch(); template Catch& operator==(T a); template Catch& operator<(T a); template Catch& operator>(T a); template Catch& operator>=(T a); template Catch& operator<=(T a); template Catch& operator||(T a); template Catch& operator&&(T a); string str(); Catch& append(string); }; int foo(int a){ return a*a - a*5 + 3; } int main() { int x = 3, y = 6; cout << "foo(a) == a*a - 5*a + 3" << endl << "x == 3, y == 6" << endl << endl << "EVAL(foo(3) == foo(-3)) :" << endl << EVAL(foo(3) == foo(-3)) << endl << endl << "EVAL(x < 4 && y > 3 || y) :" << endl << EVAL(x < 4 && y > 3 || y) << endl; return 0; } Catch::Catch() :oss() ,first(true) {} template Catch& Catch::operator<(T a){ if(!first) oss << " < "; else first = false; oss << a; return *this; } template Catch& Catch::operator==(T a){ oss << " == " << a; return *this; } template Catch& Catch::operator>(T a){ oss << " > " << a; return *this; } template Catch& Catch::operator>=(T a){ oss << " >= " << a; return *this; } template Catch& Catch::operator<=(T a){ oss << " <= " << a; return *this; } template Catch& Catch::operator||(T a){ oss << " || " << a; return *this; } template Catch& Catch::operator&&(T a){ oss << " && " << a; return *this; } string Catch::str(){ return oss.str(); } Catch& Catch::append(string s){ oss << s; return *this; }

Expression analyzer