"David Abrahams" <[EMAIL PROTECTED]> wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> Hugo Duncan <[EMAIL PROTECTED]> writes:
>
> > I am trying to use MPL to generate code.
> >
> > I have a list of types, which I would like to use to call a template
> > function with arguments that are not dependent on the list.
> >
> > eg
> >
> > given:
> > template <typename T> void my_function(std::string& s);
> > typedef list<int, float, double> my_list;
> > std::string s;
> >
> > what do I write using MPL to generate the equivalent of the following ?
> >
> > my_function<int>(s);
> > my_function<float>(s);
> > my_function<double>(s);
>
> With the latest CVS, it would be something like this:
>
> struct func
> {
> func(std::string& s) : s(s) {}
>
> template <class T>
> void operator()(T) const
> {
> my_function<T>(s);
> }
>
> private:
> std::string& s;
> };
>
> mpl::for_each<my_list>(func(s));
>
> If you have any reference or array types in my_list, you might need to
> do this instead:
>
>
> struct func
> {
> func(std::string& s) : s(s) {}
>
> template <class T>
> void operator()(mpl::identity<T>) const
> {
> my_function<T>(s);
> }
>
> private:
> std::string& s;
> };
>
> mpl::for_each<my_list, mpl::make_identity<> >(func(s));
Or (barring my lack of mastering some syntactic details):
inline void do_my_function(string&, void_) {}
template <class Lst>
inline void do_my_function(string& s, Lst lst)
{
my_function<front<Lst>::type>(s);
do_my_function(s, pop_front<Lst>::type());
}
...
do_my_function(s, my_list());
No struct, no for_each, no operator(). Et que le meilleur gagne :o).
Andrei
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