Given its prepetitive nature you could use boost preprocessor library to generate this switch...
::type); \ break; BOOST_PP_REPEAT(NUMBER_CASES, CASES, ~); }
That's a good idea. I could define #define NUMBER_CASES 4 and the switch would become something like that: switch(i) { #define CASES(z, n, text) \ case n: \ vec.push_back(new boost::mpl::at<TTypes, boost::mpl::int_<n> this compiles and works fine, but, since the number of cases in the switch must equal the size of the vector of type, I'd rather write something like: #define NUMBER_CASES boost::mpl::size<TTypes>::value but this does not compile and I am getting the error C:/ventures/test/classes/main.cpp: In member function `void Functor::operator()(const int&)': C:/ventures/test/classes/main.cpp:47: error: `BOOST_PP_REPEAT_1_boost' has not been declared C:/ventures/test/classes/main.cpp:47: error: `size' undeclared (first use this function) C:/ventures/test/classes/main.cpp:47: error: (Each undeclared identifier is reported only once for each function it appears in.) C:/ventures/test/classes/main.cpp:47: error: expected primary-expression before '>' token C:/ventures/test/classes/main.cpp:47: error: `::value' has not been declared C:/ventures/test/classes/main.cpp:47: error: `CASES' undeclared (first use this function) C:/ventures/test/classes/main.cpp:47: error: expected primary-expression before ')' token mingw32-make[1]: *** [release\main.o] Error 1 Any idea on how to make it work? Many thanks JCR "Delfin Rojas" <drojas@moodlogic.com> wrote in message news:005001c64a19$6ed5c8e0$3000a8c0@winxpme...
John Christopher wrote:
Hello, Still reading... Chapter 11 is still a few pages away... Any way, I rewrote the program and I have something much simpler. The vector of types has not changed: typedef boost::mpl::vector<T0, T1, T2, T3> TTypes; but the Functor has a new switch statement that is much easier to maintain. The nnumber of cases in the switch must be the number of elements in the vector of types... Adding new cases is no big deal anyway. switch(i) { case 0: vec.push_back(new boost::mpl::at<TTypes, boost::mpl::int_<0> >::type); break; case 1: vec.push_back(new boost::mpl::at<TTypes, boost::mpl::int_<1> >::type); break; ....
Given its prepetitive nature you could use boost preprocessor library to generate this switch...
-delfin