Question

备选方案1，重用临时变量：

Sticker sticker;
sticker.x = x + foreground.x;
sticker.y = foreground.y;
sticker.width = foreground.width;
sticker.height = foreground.height;
board.push_back(sticker);

sticker.x = x + outline.x;
sticker.y = outline.y;
sticker.width = outline.width;
sticker.height = outline.height;
board.push_back(sticker);

备选方案2，确定临时变量的范围：

{
 Sticker sticker;
 sticker.x = x + foreground.x;
 sticker.y = foreground.y;
 sticker.width = foreground.width;
 sticker.height = foreground.height;
 board.push_back(sticker);
}

{
 Sticker sticker;
 sticker.x = x + outline.x;
 sticker.y = outline.y;
 sticker.width = outline.width;
 sticker.height = outline.height;
 board.push_back(sticker);
}

备选方案3，直接写入矢量存储器：

{
 board.push_back(Sticker());
 Sticker &sticker = board.back();
 sticker.x = x + foreground.x;
 sticker.y = foreground.y;
 sticker.width = foreground.width;
 sticker.height = foreground.height;
}

{
 board.push_back(Sticker());
 Sticker &sticker = board.back();
 sticker.x = x + outline.x;
 sticker.y = outline.y;
 sticker.width = outline.width;
 sticker.height = outline.height;
}

您更喜欢哪种方式？

编辑：为了便于讨论，假设必须在构造函数之外逐个进行赋值

Answer 1

我的选项 - 为Sticker提供一个获取参数的构造函数。然后：

board.push_back( Sticker( outline.x, foo.bar, etc. ) );

编辑：用于说明构造函数参数名称的代码：

#include <iostream>
using namespace std;

struct S {
    int a, b;
    S( int a, int b ) : a(a), b(b) {
    }
};

int main() {    
    S s( 1, 2);
    cout << s.a << " " << s.b << endl;
}

Answer 2

board.resize（sticker_count）;

然后遍历所有向量并设置参数。

Answer 3

备选方案1.为什么仅为变量创建范围？附近通常有一个封闭的范围（至少，您应该保持您的功能/程序较小，以便将其范围扩大）。

为什么呢？您可以创建一个较短的变量名，例如在这种情况下。由于任务将在附近，因此不应有明显的损失。实际上它看起来更简单，更清洁。

此外，如果需要从其他几个间接级别取消引用/访问向量，那么它也将简化代码。

Answer 4

winforms风格怎么样：

// Class members

Sticker sticker1;
Sticker sticker2;
Board board;

// Initialization 

void InitBoard()
{
    sticker1.x = x + foreground.x;
    sticker1.y = foreground.y;
    sticker1.width = foreground.width;
    sticker1.height = foreground.height;

    sticker2.x = x + outline.x;
    sticker2.y = outline.y;
    sticker2.width = outline.width;
    sticker2.height = outline.height;

    // Add to board
    board.push_back(sticker1);
    board.push_back(sticker2);
}

填充结构的C ++向量的首选方法

4 个答案: