G'day all.
On Feb 10, 2008 3:40 PM, Mattes Simeon wrote:
Though in comparison with C or C++ I can't figure out so clear the syntax.
Quoting Victor Nazarov :
I think this is the most native way to do it in C++:
Herb Sutter and Andrei Alexandrescu will find you and beat you up if
you write this. This is considered more appropriate. (Warning: untested
code follows.)
#include
template
class Tuple : public boost::variant >
{
private:
typedef std::pair pair_type;
typedef boost::variant base_type;
struct visitor_A : public boost::static_visitor
{
const A* operator()(const A& a) { return &a; }
const A* operator()(const pair_type& p) { return &p.first; }
};
public:
Tuple(const A& a)
: base_type(a)
{
}
Tuple(const A& a, const B& b)
: base_type(pair_type(a,b))
{
}
const A* tuple1() const
{
return boost::apply_visitor(visitor_A(), *this);
}
const B* tuple2() const
{
const pair_type* p = boost::get(*this);
return p ? &p->second : 0;
}
};
But in this specific case, this might be more appropriate:
template
class Tuple
{
A m_a;
boost::optional<B> m_b;
// etc
};
Cheers,
Andrew Bromage
