which boost lib to use for generic list sort by member function ?

From: Philippe Guglielmetti (yg-boost-users_at_[hidden])
Date: 2003-01-09 04:22:47

I try to define a "sortby" method that would sort a list using any member
function that fits some constraints (taking no parms, returning a result
that can be compared using the > operator and being const)

I wrote this:

template <class T>
class mylist:public std::list<T>
{ // ...
template <typename T2, typename R, R (T2::*F)() const>
struct cmp: public std::binary_function<T,T,bool>
{
  bool operator()(const T& f1, const T& f2) {return (f1.F)() > (f2.F)();};
};

template <typename T2, typename R>
bool sortby(R (T2::*F)() const)
{
  sort(cmp<T,R,F>());
  return true;
};
}; // class mylist

using VC6 (I know...) I get these 3 errors:

algos.h(356) : error C2440: 'specialization' : cannot convert from 'double
(__thiscall cadoo::cadFace::*)(void) const' to 'double (__thiscall
cadoo::cadFace::*)(void)'
algos.h(356) : error C2975: 'cmp' : invalid template argument for 'F',
constant expression expected
algos.h(356) : error C2514: 'dyl::List<class cadoo::cadFace>::cmp<class
cadoo::cadFace,double,0>' : class has no constructors

any idea ? I also checked boost.org for help on functors, lambda ... but
could not figure out how to use them simply for my application.
thanks!

Philippe Guglielmetti