无法从“初始化列表”转换

问题描述 投票:0回答:3

我是新手,在C ++中有问题。我正在创建3D坐标,(面部每个角落的x,y和z,然后是6个面)并收到许多错误。这是我的代码:

#include <vector>
int main()
{
    std::vector<int> xyzCoords = {
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
    };

    int x1 = 0;
    int y1 = 1;
    int z1 = 2;
    int x2 = 3;
    int y2 = 4;
    int z2 = 5;

    xyzCoords = {
    { x1, y1, z1, x2, y1, z1, x2, y1, z2, x1, y1, z2 },
    { x1, y2, z1, x2, y2, z1, x2, y2, z2, x1, y2, z2 },
    { x1, y2, z1, x1, y1, z1, x1, y1, z2, x1, y2, z2 },
    { x2, y2, z1, x2, y1, z1, x2, y1, z2, x2, y2, z2 },
    { x1, y2, z2, x1, y1, z2, x2, y1, z2, x2, y2, z2 },
    { x1, y2, z1, x1, y1, z1, x2, y1, z1, x2, y2, z1 }
    };
    return 0;
}

这是出现问题的代码。你可以看到我将xyzCoords定义为向量。我不确定这是否是正确的方法。我也不想单独定义xyz123。实现这一目标的最佳方法是什么?我要使用列表,数组还是向量?请写下如何执行此操作的代码。谢谢!错误:

E0289:没有构造函数的实例“std :: vector <_Ty,_Alloc> :: vector [with _Ty = int,_Alloc = std :: allocator]”匹配参数列表

E0349:没有运算符“=”匹配这些操作数

C2440:'初始化':无法从'初始化列表'转换为'std :: vector>'

C2679:binary'=':找不到哪个运算符采用'初始化列表'类型的右手操作数(或者没有可接受的转换)

c++ arrays list vector initialization
3个回答
2
投票

您的初始化与您声明的类型不匹配。声明一维数组,而初始化是二维数组。

std::vector<int> xyzCoords = {
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};

它应该是 :

std::vector<std::vector<int>> xyzCoords = {
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};

你提到过xyz坐标,所以你为什么不创建一个专门用于坐标的类,例如:

struct Point {
   int x, y, z;
}; 

无论如何,我不建议你使用朴素的方法来解决这个问题,因为它将是一个矩阵操作密集型计算。您应该使用BLAS / LAPACK库或它的包装,如EigenArmadillo。他们肯定要快得多。


2
投票

也许你应该将你的代码重构为这样的东西,以获得可见性和更好的理解:

#include <vector>

int main()
{
    struct Corner
    {
        int x;
        int y;
        int z;
        Corner(int x, int y, int z) :
            x(x), y(y), z(z) {}
    };

    struct Face
    {
        Corner c1;
        Corner c2;
        Corner c3;
        Corner c4;
        Face(Corner c1, Corner c2, Corner c3, Corner c4) :
            c1(c1), c2(c2), c3(c3), c4(c4) {}
    };

    Corner c1(0, 1, 2);
    Corner c2(3, 4, 5);
    Face f1(c1, c2, c1, c2);

    std::vector<Face> faces = { f1, f1, f1, f1, f1, f1 };

    return 0;
}

这将创建6个面的数组,其角坐标(x1,y1,z1)(x2,y2,z2)(x1,y1,z1)(x2,y2,z2)


2
投票
#include <vector>

struct Vertex {
    float x_; // can change these to int
    float y_;
    float z_;
    Vertex() : x_(0), y_(0), z_(0) {}
    Vertex( float x, float y, float z ) : x_(x), y_(y), z_(z) {}
    explicit Vertex( float val ) : x_(val), y_(val), z_(val) {}
};

struct Face {
    Vertex v0_;
    Vertex v1_;
    Vertex v2_;
    Vertex v3_;

    Face() : 
    v0_(Vertex()), 
    v1_(Vertex()),
    v2_(Vertex()), 
    v3_(Vertex()) {
    }

    Face( Vertex v0, Vertex v1, Vertex v2, Vertex v3 ) :
    v0_(v0),
    v1_(v1),
    v2_(v2),
    v3_(v3) {
    }          
};

int main() {
    std::vector<Face> faces;

    // Not exact values the OP is looking for,
    // just a quick way to populate the vector of faces
    // for demonstration purposes of the usefulness of structs & classes.
    for ( unsigned n = 1; n <= 6; n++ ) {
        faces.push_back( Face( Vertex(n), Vertex(n+1), Vertex(n+2), Vertex(n+3) ) );
    }        

    return 0;
}
© www.soinside.com 2019 - 2024. All rights reserved.