I have the following code:
template<typename Parent, typename T, void (Parent::*Setter)(T), T (Parent::*Getter)()>
struct Property {
Parent& obj;
Property(Par开发者_如何学Goent& _obj) : obj(_obj) {}
Property& operator=(T v) { (obj.*Setter)(v); return *this; }
operator T() { return (obj.*Getter)(); }
};
template<typename T1, typename T2>
class Bimap {
public:
class Entry;
typedef std::tr1::shared_ptr<Entry> EntryP;
typedef std::multimap<T1, EntryP> T1Map;
class Entry {
private:
Bimap& bimap;
typename T1Map::iterator it1;
void set1(T1 v) { bimap.map1.erase(it1); it1 = bimap.map1.insert(typename T1Map::value_type(v, it2->second)).first; }
T1 get1() { return it1->first; }
public:
Property<Entry,T1,set1,get1> first() { return Property<Entry,T1,set1,get1>(*this); }
};
};
This code gives me (on Property<...> first()
):
'void Bimap<T1, T2>::Entry::set1(T1) [with T1 = double, T2 = std::tr1::shared_ptr<Node>]' cannot appear in a constant-expression
I also tried with
Property<Entry,T1,&set1,&get1> first() { return Property<Entry,T1,&set1,&get1>(*this); }
but that gives me:
error: wrong number of template arguments (3, should be 4)
error: provided for 'template<class Parent, class T, void (Parent::* Setter)(T), T (Parent::* Getter)()> struct Property'
Is it possible to fix this somehow? Or why is that not possible?
You want
Property<Entry, T1, &Entry::set1, &Entry::get1>
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