C ++ 0x：在多个迭代器上应用函数
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我正在尝试编写一个可以在多个迭代器上映射一个函数的函数。就像
template <class Fun>
fun_over_variadic_args(Fun fun) { }
template <class Fun, class First, class Rest...>
fun_over_variadic_args(Fun fun, First& first, Rest&... rest) {
fun(first);
fun_over_variadic_args(fun, rest...);
}
namespace {
template <class T> struct thunk_inc {
decltype(T::operator++()) operator()(T& t) { return ++t; }
};
}
template <class Fun, class MainIterator, class RestOfIterators...>
std::tuple<MainIt&, RestOfIts&...> map_over_iterators(Fun fun, MainIt& it, MainIt& end, RestOfIts&... rest) {
const thunk_inc();
for (; it!=end; fun_over_variadic_args(thunk_inc, it, rest...)) {
// Do something
}
}
template <class... T>
void foo(T... t) { }
template <class... Arg>
void test(Arg... arg) {
foo(fun(arg)...); // Works!
fun(arg)...; // Doesn\'t work!
}
没有找到相关结果
已邀请:
1 个回复
曝匿弄罚
template <typename ItHead, typename... ItTail> void advance_iterators(ItHead & it, ItTail ...others) { ++it; advance_iterators(others...); } template <typename It> void advance_iterators(ItHead & it) { ++it; } template <typename Fun, typename ItMain, typename ...ItOthers> apply_helper(Fun & f, ItMain it, ItOthers ...others) { f(*it); apply_helper(f, others...); } template <typename Fun, typename ItMain, typename ...ItOthers> apply_helper(Fun & f, ItMain it) { f(*it); } template <typename Fun, typename ItMain, typename ...ItOthers> apply (Fun & f, ItMain begin, ItMain end, ItOthers ...others) { while (begin != end) { apply_helper(f, begin, others...); advance_iterators(begin, others...); } }同时对所有值进行运算，那么您应该摆脱，而只需调用并创建一个函数即可使用所有这些迭代器。