如何设置全局容器（C ++ 03）？ [英] How to setup a global container (C++03)?

问题描述

我想定义一个全局容器（C ++ 03），这里是一个示例代码，我试过，这不工作。

I want to define a global container (C++03), and here's an example code I tried, which does not work.

#include <vector>
#include <string>
using namespace std;

vector<string> Aries;
Aries.push_back("Taurus");    // line 6

int main() {}

编译错误：

prog.cpp:6:1: error: 'Aries' does not name a type

看来我可以定义一个空的全局向量，但不能填满它。看起来像在C ++ 03中，我不能指定初始化器，例如：

It seems I can define an empty global vector, but cannot fill it up. Looks like in C++03, I cannot specify an initializer either, such as:

vector<string> Aries = { "Taurus" };

我在这里犯了一个错误，或者如何解决这个问题？

Have I made a mistake here, or how do I get around this problem?

我尝试在StackOverflow上搜索，看看这是否已经回答了，但只有遇到这些帖子： C ++中的全局对象，定义

I tried searching on StackOverflow to see if this has been answered before, but only came across these posts: global objects in C++, Defining global constant in C++, which did not help answer this.

推荐答案

我发现了一个简洁的解决方法来初始化 C ++ 03全局STL容器（并且实际上在 main（）之前全局地执行代码）。这使用逗号运算符。请参阅示例：

I found a neat workaround to "initialize" C++03 global STL containers (and indeed to execute code "globally" before main()). This uses the comma operator. See example:

#include <vector>
#include <string>
#include <iostream>
using namespace std;

vector<string> Aries;

// dummy variable initialization to setup the vector.
// using comma operator here to cause code execution in global scope.
int dummy = (Aries.push_back("Taurus"), Aries.push_back("Leo"), 0);

int main() {
    cout << Aries.at(0) << endl;
    cout << Aries.at(1) << endl;
}

输出

Taurus
Leo

你可以调用它，是额外的全局变量。

The only real problem, if you can call it that, is the extra global variable.

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