Method test_xy

exprtk_test.cpp:1311–1316

struct test_xy
{
   test_xy(const std::string& e, const T& v0, const T& v1, const T& r)
   : expr(e)
   , x(v0)
   , y(v1)
   , result(r)
   {}

   std::string expr;
   T x;