一个头文件中初始化定制结构的向量 [英] Initialize a vector of customizable structs within an header file

问题描述

有什么办法让全球结构的列表，并初始化包含它们的修改版本来自同一头文件中的向量？
我知道我不能直接从h文件访问和编辑的变量，因为它不是运行时code，但也许有恰好是一个解决方法这一点 - 也许，我只是碰巧一些很基本的方式跳过对C ++初学者手册..如果是的话请原谅！

Is there any way to have a list of global structs and initialize a vector containing modified version of them from within the same header file? I know I can't directly access and edit variables from an .h file, since it's not run-time code, but maybe there happens to be a workaround to this - or maybe some very basic way that I just happened to skip on the C++ Beginners manual.. pardon me if so!

要做出一个例子，假设我有一个COM prehends几个成员的结构，并宣布在.h文件中一些全局的人。

To make an example, let's say I have a struct which comprehends a couple of members, and declared some global ones in the .h file..

struct MyStruct
{
  unsigned int a;
  string foo;
  float myfloat;
};

MyStruct struct_one={1,"hello",0.238f};
MyStruct struct_two={10,"salve",3.14f};
MyStruct struct_three={3,"bonjour",0.001f};
MyStruct struct_four={6,"dias",5.0f};

然后我就可以初始化包含它们的这种方式（不知道这是否是最好的一个，虽然）

I can then initialize a vector containing them this way (don't know if it's the best one though)

MyStruct MyStructArray[] = {struct_one, struct_two, struct_three, struct_four};

vector<MyStruct> MyStructVector(MyStructArray,
MyStructArray+sizeof(MyStructArray)/sizeof(MyStructArray[0]));

不过，我想能够改变，对飞，一些结构的成员创造不改变全局对象的向量（或阵列）之前。
可能吗？

But I would like to be able to change, on the fly, some of the structs' members before creating the vector (or the array) without changing the global ones. Possible?

编辑：通过一个头文件中的我的意思是，一个头文件中。如果我做 unsigned int类型A = 100; 在标题中，我没有初始化或拨打东西在实际来源，使其工作。本身矢量完​​美的作品，我只是想知道是否有从原来的全球结构的修改版本构建它的方式..说，我想用相同的全局结构，但对成员不同的值 A 。

By "within an header file" I meant, "within an header file". If I do unsigned int a = 100; in the header, I don't have to initialize or call something in the actual source to make it work. The vector by itself works perfectly, I only wanted to know if there was a way to build it from modified versions of the original global structs.. say, I want to use the same global structs, but with different values for member a.

推荐答案

在@Sam的回答之上...

On top of @Sam 's answer...

使用构造函数：

struct MyStruct {
    unsigned int a;
    string foo;
    float myfloat;

    MyStruct(unsigned int a, const string& foo, float myfloat) : a(a) , foo(foo), myfloat(myfloat) {}
};

现在你可以用一个简单的声明你的结构添加到载体

Now you can add your struct to the vector with a simple statement

vec.push_back(MyStruct(1, "hello", 0.238f));

---

class Foo {
public:
    static std::vector<int> MyStructVector;
}

inline std::vector<MyStruct> MakeVector()
{
    std::vector vec;
    vec.push_back(MyStruct(1, "hello", 0.238f));
    //...
    return vec;
}

std::vector<MyStruct> Foo::MyStructVector= MakeVector();

这篇关于一个头文件中初始化定制结构的向量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！