将unique_ptr的向量插入另一个向量 [英] Inserting a vector of unique_ptr into another vector

问题描述

我有一个unique_ptr的向量，我想将它们附加到另一个unique_ptrs的向量。我通常会做一个简单的插入：

I have a vector of unique_ptr's and I want to append them to another vector of unique_ptrs. I would normally do a simple insert:

std::vector<std::unique_ptr<foo>> bar;
bar.push_back(std::unique_ptr<foo>(new foo(1)));
std::vector<std::unique_ptr<foo>> baz;
baz.push_back(std::unique_ptr<foo>(new foo(2)));
bar.insert(bar.end(), baz.begin(), baz.end());

但是这会给我类似的编译错误：

However this gives me compile errors similar to this:

/usr/include/c++/4.8/bits/stl_algobase.h:335: error: use of deleted function 'std::unique_ptr<_Tp, _Dp>& std::unique_ptr<_Tp, _Dp>::operator=(const std::unique_ptr<_Tp, _Dp>&) [with _Tp = foo; _Dp = std::default_delete<foo>]'
    *__result = *__first;
              ^

有一种方便的方式插入或者我必须遍历baz和push_back上吧？我目前正在使用gcc 4.8.1。

Is there a convenient way to insert or do I have to iterate over baz and push_back on bar? I'm currently using gcc 4.8.1.

感谢

推荐答案

unique_ptr 是不可分配的正常赋值运算符（错误说它被删除）。您只能移动：

unique_ptr is not assignable with normal assignment operator (the error says it's deleted). You can only move them:

bar.insert(bar.end(),
    std::make_move_iterator(baz.begin()),
    std::make_move_iterator(baz.end())
);

当然，这会传输托管对象的所有权，原始指针将具有 nullptr 值。

Of course, this transfers the ownership of the managed object and original pointers will have nullptr value.

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