visual c ++为什么std :: move崩溃

Question

我想在另一个向量的末尾追加一个向量.据我所知,该功能std::move()是此任务的"选择功能".为什么std::move()在手工制作的循环按预期工作时,Microsoft Visual C++ Express会崩溃？

我使用的是Microsoft Visual C++ 2015 Update 3.不幸的是,我无法使用其他编译器对此进行测试.

// The setup code for the two vectors:
vector<unique_ptr<channel>> channels, added_channels;

// ...  here is some code that adds some elements to both vectors

根据我的知识,以下两段代码应该以相同的方式工作.他们应该把元素added_channels移到最后channels.

这是第一个崩溃的变种:

std::move(added_channels.begin(), added_channels.end(), channels.end());

这是第二个有效的版本:

for(auto & ref : added_channels)
{
    channels.push_back(std::move(ref));
}

Answer 1

std :: move移动到特定位置.
如果要将其插入向量的背面,则应使用std :: back_inserter

std::move(added_channels.begin(), added_channels.end(),  std::back_inserter(channels));

Answer 2

This is actually one of the few cases where a move_iterator is actually useful:

channels.insert(channels.end(), 
                std::make_move_iterator(added_channels.begin()), 
                std::make_move_iterator(added_channels.end()));

For insertion into a vector, range insert is preferable to element-by-element push_back (or the equivalent back_inserter) because it avoids unnecessary reallocations and correctly grows the storage exponentially. The latter is easy to mess up: indiscriminate uses of reserve can easily cause quadratic behavior.