从std :: tuple成员中删除引用

Question

我在stl元组的帮助下为一些变量实现了保存/恢复功能,如下所示:

double a = 1, b = 2;
int c = 3;
auto tupleRef = std::make_tuple(std::ref(a), std::ref(b), std::ref(c));

// here I'm saving current state of a, b, c
std::tuple<double, double, int> saved = tupleRef;

//here goes block of code, where a, b, and c get spoiled
......................
//

//now I'm restoring initial state of a, b, c
tupleRef = savedTuple;

这段代码效果很好.但不是明确指定元组成员类型

std::tuple<double, double, int> saved = tupleRef;

我想宁愿删除所有tupleRef成员的引用,如下所示

auto saved = remove_ref_from_tuple_members(tupleRef);

我相信可以为此编写"remove_ref_from_tuple_members"模板.

谢谢你的回答.

Answer 1

可以使用简单类型别名来应用std::remove_reference元组中的所有类型.

template <typename... T>
using tuple_with_removed_refs = std::tuple<typename std::remove_reference<T>::type...>;

有了这个,您现在可以编写功能模板:

template <typename... T>
tuple_with_removed_refs remove_ref_from_tuple_members(std::tuple<T...> const& t) {
    return tuple_with_removed_refs { t };
}