Question

无论如何都要避免做这样的事情：

std::queue<myStruct>  part1, part2, part3, part4, part5, part6, part7, part8, part9, part10;

void setup(){
myVector.push_back(part1);
myVector.push_back(part2);
myVector.push_back(part3);
myVector.push_back(part4);
myVector.push_back(part5);
myVector.push_back(part6);
myVector.push_back(part7);
myVector.push_back(part8);
myVector.push_back(part9);
myVector.push_back(part10);
}

虽然这只能达到第10部分，但我可能会达到50或更高。它只是编码的一部分，它必须在某个地方声明，或者是否有动态的方式我可以声明并将这些队列分配给myVector，而不用这样写它？

TIA

Answer 1

一个简单的方法：

std::vector<std::queue<myStruct>> myVector(10);

完成！

Answer 2

假设你的结构看起来像这样：

struct myStruct{

    //random variables that your struct may contain
    int num;
    std::string str;
    char ch;

    //Default Constructor
    //This allows your to create your structs without specifying any values;
    myStruct():
    num{999},str{"default"},ch{'z'}{}

    //Parameterized Constructor
    //This allows you to create your structs with specified values during initialization
    myStruct(int const numIn, std::string const& strIn, char const chIn):
    num{numIn},str{strIn},ch{chIn}{}

};

这将允许您通过以下方式创建实例：

//calling default constructor
myStruct part1, part2, part3;

//calling parameterized constructor
myStruct part4{4,"4",'4'}, part5{5,"5",'5'}, part6{6,"6",'6'};

现在您想将每个容器放入容器中，然后将这些容器放入另一个容器中吗？

//this is a vector holding one deque holding 6 structs
vector<deque<myStruct>> vec{{part1,part2,part3,part4,part5,part6}};
+-------+
|  vec  |
|       |
|  [0]  |
+-------+
    |
   \'/
+-------+
|  deq  |
|       |-> part1
|  [0]  |
+-------+
|  deq  |
|       |-> part2
|  [1]  |
+-------+
|  deq  |
|       |-> part3
|  [2]  |
+-------+
|  deq  |
|       |-> part4
|  [3]  |
+-------+
|  deq  |
|       |-> part5
|  [4]  |
+-------+
|  deq  |
|       |-> part6
|  [5]  |
+-------+


//this is a vector holding 6 deques each holding 1 struct
vector<deque<myStruct>> vec2{{part1},{part2},{part3},{part4},{part5},{part6}};
+-------++-------++-------++-------++-------++-------+
|  vec  ||  vec  ||  vec  ||  vec  ||  vec  ||  vec  |
|       ||       ||       ||       ||       ||       |
|  [0]  ||  [1]  ||  [2]  ||  [3]  ||  [4]  ||  [5]  |
+-------++-------++-------++-------++-------++-------+
    |        |        |        |        |        |
   \'/      \'/      \'/      \'/      \'/      \'/
+-------++-------++-------++-------++-------++-------+
|  deq  ||  deq  ||  deq  ||  deq  ||  deq  ||  deq  |
|       ||       ||       ||       ||       ||       |
|  [0]  ||  [0]  ||  [0]  ||  [0]  ||  [0]  ||  [0]  |
+-------++-------++-------++-------++-------++-------+
    |        |        |        |        |        |
   \'/      \'/      \'/      \'/      \'/      \'/
  part1    part2    part3    part4    part5    part6

我们可以做些更好的事情。让我们初始化你的结构，同时将它们推入双端队列，同时将双端队列推入向量中。

//this is a vector holding one deque holding 6 structs
vector<deque<myStruct>> vec{{{1,"1",'1'},{2,"2",'2'},{3,"3",'3'},{4,"4",'4'},{5,"5",'5'},{6,"6",'6'}}};

//this is a vector holding 6 deques each holding 1 struct
vector<deque<myStruct>> vec2{{{1,"1",'1'}},{{2,"2",'2'}},{{3,"3",'3'}},{{4,"4",'4'}},{{5,"5",'5'}},{{6,"6",'6'}}};

请记住，这是所有C ++ 11初始化功能。我建议你阅读这篇文章来习惯。 http://www.informit.com/articles/article.aspx?p=1852519

要编译这样的代码，请确保您的编译器是最新的，并且您具有相应的库文件。如果您使用gcc，请使用此标志进行编译：

g ++ -std = c ++ 0x -o main main.cpp

优化声明重复变量？

2 个答案: