Runtime support for searchables

[jupp0r]

This doesn't compile

#include <boost/hana.hpp>
#include <boost/hana/ext/std/tuple.hpp>
#include <boost/optional.hpp>

bool f() {
    auto t = std::make_tuple(boost::optional<int>{boost::none}, boost::optional<int>{4});
    return boost::hana::all(t);
}

This does, but not under MSVC (it rightfully complains that the lambda passed to all_of needs to return a Logical.

#include <boost/hana.hpp>
#include <boost/hana/ext/std/tuple.hpp>
#include <boost/optional.hpp>

bool f() {
    auto t = std::make_tuple(boost::optional<int>{boost::none}, boost::optional<int>{4});
    return boost::hana::all_of(t, [](auto v) { return static_cast<bool>(v); });
}

This compiles everywhere, but is suboptimal due to lack of early return:

#include <boost/hana.hpp>
#include <boost/hana/ext/std/tuple.hpp>
#include <boost/optional.hpp>

bool f() {
    auto t = std::make_tuple(boost::optional<int>{boost::none}, boost::optional<int>{4});
    return boost::hana::fold(t, true, [](bool state, auto v) {
        return state && static_cast<bool>(v);
    });
}

Reading through the documentation, I couldn't find any information about runtime support of algorithms. Is this a bug or an expected limitation?