removed timeit def constr

Author: kr-2003

src/xmagics/execution.cpp

@@ -35,10 +35,6 @@ namespace xcpp
 
     int timeit::exec_counter = 0;
 
-    timeit::timeit()
-    {
-    }
-
     void timeit::get_options(argparser& argpars)
     {
         argpars.add_description("Time execution of a C++ statement or expression");

src/xmagics/execution.hpp

@@ -23,15 +23,15 @@ namespace xcpp
     {
     public:
 
-        timeit();
-
+        XEUS_CPP_API
         virtual void operator()(const std::string& line) override
         {
             std::string cline = line;
             std::string cell = "";
             execute(cline, cell);
         }
 
+        XEUS_CPP_API
         virtual void operator()(const std::string& line, const std::string& cell) override
         {
             std::string cline = line;