Cast Chars To Int in Template Function

问题

I have a C++ template function which prints numbers.

It works fine for everything, except when I'm working with data of type char.

I'd like char to be printed as int, but if I cast this explicitly in the template function, then I will lose precision on my float types.

I'd like to be able to say:

template<class T> bob(T a){
  cout<<if_char_make_int(a)<<endl;
}

But I'm not sure how to do this, or if it is possible.

Any thoughts?

回答1:

template<class T> void bob(T a){
    std::cout
      << typename boost::mpl::if_<boost::is_same<char, T>, int, T>::type(a)
      << std::endl;
}

回答2:

template<class T> void bob(T a){
  cout<< a <<endl;
}

template<> void bob(char a){
  cout<< static_cast<int>(a) <<endl;
}

For more please read here http://www.cplusplus.com/doc/tutorial/templates/ (Template specialization)

Hope it helps

来源：https://stackoverflow.com/questions/9764295/cast-chars-to-int-in-template-function