C ++在向量中的好奇行为:: push_back（） [英] C++ curious behavior in vector::push_back()

问题描述

我有一个名为Task的类的数据结构：

I have the following data-structure as a class named "Task":

private:
string name;
int computation_time;
int period;

此外，我有一个ASCII文件与此内容：

Furthermore i have a ASCII-File with this content:

A 3 10
B 2 12
C 1 11

name = A，computation_time = 3，period = 10 and so on ....

name = A, computation_time = 3, period = 10 and so on....

现在我想读文件，创建Task对象并将其推回到向量中：

Now i want to read in the file, create Task-object and push it back into a vector:

void read_in_task_list_and_create_tasks(const string &filename, vector<Task> &current_tasks)
{
    ifstream in_file;
    in_file.open(filename.c_str());

    string tmp_name;
    int tmp_computation_time;
    int tmp_period;

    while(!in_file.eof())
    {
        in_file >> tmp_name;
        in_file >> tmp_computation_time;
        in_file >> tmp_period;

//        Task tmp_task(tmp_name, tmp_computation_time, tmp_period);
//        current_tasks.push_back(tmp_task);
        current_tasks.push_back(Task(tmp_name, tmp_computation_time, tmp_period));
    }
}

现在，当我查看current_tasks向量时，它有元素，但它们的值不匹配我的in_file值。
观看取消注释的行。

Now, when i take a look into current_tasks vector, it has elements, but their values dont match my in_file values. Watch the outcommented lines. tmp_task object is exactly correct, but if it's getting pushed back, it loses it's values like descriped above.

这可能是Task-Class中的一个复制 - 构造函数，因为它是一个复制 - 构造函数std :: vector正在管理内存分配？

Could this be a Copy-Constructor Issue in Task-class, because std::vector is managing the memory-allocation?

我在Linux x86上使用带有g ++编译器的netbeans。

I'm using netbeans with g++ compiler on Linux x86.

THX

推荐答案

确保没有定义复制构造函数或赋值运算符。

Make sure there are no copy constructors or assignment operators defined.

自动的应该做你想要的。

The automatic ones should do exactly what you want.

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