mpl::equal for associative sequences

[anonymous]

this is not a bug, as the current behaviour is documented correctly, but I think mpl::equal<> should return equality for mpl::set<>s that are equal but are not in the same sequence. something like:

struct equal :

mpl::and_<

mpl::equal_to<

mpl::size<Set1>, mpl::size<Set2>

,

mpl::fold<

Set1, mpl::true_, mpl::and_<

mpl::_1, mpl::has_key<Set2,mpl::_2>

{};

also I think it would be usable for equal sets to be runtime-convertible.

template<...> struct set{

template<class OtherSet> set(OtherSet,typename enable_if<equal<set,OtherSet> >::type *e=0){}

};

so you can do this:

void f(set<e1,e2>);

f(set<e2,e1>());

the same might be usable for mpl::map.

[Steven Watanabe]

mpl::equal is the equivalent of std::equal. Adding a special case for set would be a bad idea.

[anonymous]

ok, so mpl::equal was the wrong choice, but there is still no easy way to compare two sets for equality. std::set<>s have operator==. so mpl::equal_to might be the right choice.