myVector vec;
vec.push_back(Point(3,5));
vec.push_back(Point(4,6));
vec.push_back(Point(6,3));
vec.fsort(Point::getx);
class myVector
{
//stuff
template <class U>
void fsort(U (T::*func)())
{
//sorting algorythm
}
}
Quote:creating pointer to member function of non-class type `int'
bool CompareX(const Point& p1, const Point& p2) { return p1.getx() < p2.getx(); }// ...std::vector<Point> points;// ...std::sort(points.begin(), points.end(), &CompareX);Quote:Original post by WindScar
No, I don't want a function like "comparex", because that would require writing new "compare" functions everytime I store a new kind of object in the vector, or there's a new kind of variable I want to sort from. I just want the vector class totally independent from the type of object I want it to store. Passing the function pointer gives me that. Not CompareX, yes Compare(T::getx). Is that possible?
template<class T>bool is_less(const T& t1, const T& t2) { return t1 < t2; }class Bar{};class Foo{public: bool do_compare(const Bar& b1, const Bar& b2) const { }};int main(int argc, char** argv){ std::vector<Bar> v; Foo comparer; std::sort(v.begin(), v.end(), boost::bind(&Foo::compare, &comparer, _1, _2));} std::vector<Bar> v; std::sort(v.begin(), v.end(), [](const Bar& b1, const Bar& b2) { b1.x < b2.x; } );#include <algorithm>#include <cstdlib>#include <iostream>template <class T>class myVector{ template <class T, class U> struct mappedCompare { U (T::*func)() const; mappedCompare(U (T::*func)() const) : func(func) {} bool operator()(const T& l, const T& r) const { return (l.*func)() < (r.*func)(); } };public: T data[10]; // hack for demo template <class U> void fsort(U (T::*func)() const) { std::sort(data, data + 10, mappedCompare<T, U>(func)); }};class widget { // hack for demo int width, height;public: widget() : width(std::rand() % 100), height(std::rand() % 100) {} int getheight() const { return height; }};int main() { // hack for demo myVector<widget> v; v.fsort(&widget::getheight); for(int i = 0; i < 10; ++i) std::cout << i << ": " << v.data.getheight() << "\n";}Quote:error: creating pointer to member function of non-class type `int'
template <class U> void fsort(U comparator) { std::sort(data, data + 10, comparator); } void fsort() { std::sort(data, data + 10); }// usagemyVector<widget> v;v.fsort(mappedCompare<widget, int>(&widget::getheight));myVector<int> v2;v.fsort();Quote:Original post by WindScarAll of these could be implemented as free functions taking a std::vector as a parameter, and indeed, this would be much more sensible.
For adding some extra functions like that spetial sort, a null pointer remover, a operator<< overload ;
Heeeeelp!
