在列表中存储未来 [英] Storing a future in a list

问题描述

我想将使用异步生成的多个线程的期货存储在列表中，以便以后检索它们的结果.

I want to store the futures of several threads spawned using async in a list to retrieve their results later.

future<int> f = async(doLater, parameter);
list<future<int>> l;
l.push_back(f);

但是编译器会显示以下错误消息

However the compiler prints the following error message

/usr/include/c ++/4.7/bits/stl_list.h:115:71:错误:使用已删除的函数'std :: future< _Res> :: future(const std :: future< _Res>& )[with _Res = int; std :: future< _Res> = std :: future]'

/usr/include/c++/4.7/bits/stl_list.h:115:71: error: use of deleted function 'std::future<_Res>::future(const std::future<_Res>&) [with _Res = int; std::future<_Res> = std::future]'

我做错什么了吗?不是应该存储期货的清单吗?如果不是，那该怎么用呢?

Am i doing something wrong or aren't lists supposed to store futures? If they are not, what to use instead?

推荐答案

std::future是不可复制的-您需要进入列表.要么

std::future is not copyable - you need to move into the list. Either:

future<int> f = async(doLater, parameter);
list<future<int>> l;
l.push_back(std::move(f));

或:

list<future<int>> l;
l.push_back(async(doLater, parameter));

将起作用，后者是更可取的，因为它不会使移出的对象乱扔范围.

will work, with the latter being preferable since it doesn't leave a moved-from object littering the scope.

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