我遇到了段错误，并通过简化main（）函数并使用valgrind来缩小出现问题的范围。

main.cpp

int main() {
    unique_ptr<Graph> g1 = make_unique<Graph>();
    unique_ptr<Graph> g2 = make_unique<Graph>();
    for (int i = 0; i < 10; i++) {
        g1->insert(1,0+i,1+i);
        cout << i << endl;
        g2 = g1->copy();
    }
}

使用valgrind时程序的输出：

0
1
==10545== Invalid read of size 8
==10545==    at 0x110612: std::vector<unsigned int,std::allocator<unsigned int> >::push_back(unsigned int const&) (in /home/user/Program/C++/main)
==10545==    by 0x1176F9: Graph::insert(unsigned int,unsigned int,unsigned int) (in /home/user/Program/C++/main)
==10545==    by 0x117D5B: Graph::copy() (in /home/user/Program/C++/main)
==10545==    by 0x10D5DA: main (in /home/user/Program/C++/main)
==10545==  Address 0x10 is not stack'd,malloc'd or (recently) free'd

当我尝试在增加大小（默认矩阵为2x2）后尝试复制Graph对象时，似乎发生SEGFAULT。我不知道为什么会这样，我只知道在matrix[n1][n2]->v.push_back(value)中到达insert()时会发生这种情况

图形类（简体）：

class Graph {
    private:
        struct Edge {
            // fields... 
            vector<unsigned int> v;
            // functions...
        }

        unsigned int size = 2;

        vector<vector<shared_ptr<Edge>>> matrix = vector<vector<shared_ptr<Edge>>>(size,vector<shared_ptr<Edge>>(size));

        void resize(unsigned int newSize) {
            matrix.resize(newSize);
            for (unsigned int i = 0; i < newSize; i++) {
                matrix[i].resize(newSize);
            }
            if (newSize > size) {
                for(unsigned int j = 0; j < newSize-1; j++) {
                    matrix[j][newSize-1] = make_shared<Edge>();
                    matrix[newSize-1][j] = matrix[j][newSize-1];
                }
                matrix[newSize-1][newSize-1] = matrix[0][0];
            }
            size = newSize;
        }

    public:
        Graph() { // matrix[i][j] = matrix[j][i],matrix[i][i] = invalid
            shared_ptr<Edge> E = make_shared<Edge>();
            shared_ptr<Edge> other = make_shared<Edge>(); // placeholder,not to be used
            matrix[0][0] = other;
            matrix[0][1] = E;
            matrix[1][0] = E;
            matrix[1][1] = other;
        }

        ~Graph() {
            vector<vector<shared_ptr<Edge>>>().swap(matrix);
        }

        char insert(unsigned int value,unsigned int n1,unsigned int n2) {
            if (n1==n2) return 0;
            if (n1 > n2) {
                int temp = n1;
                n1 = n2;
                n2 = temp;
            }
            if (value==0 || n2>size || (n2==size&&n1 < size-1)) return 0;
            if (n2 == size) {
                resize(size+1);
            }
            matrix[n1][n2]->v.push_back(value); // SEGFAULT HERE!!
            return 1;
        }

        // segfault seems to happen when resizing ? 
        unique_ptr<Graph> copy() {
            unique_ptr<Graph> thisCopy = make_unique<Circuit>();
            if(size!=2) thisCopy->resize(size);
            for (unsigned int i = 0; i < size-1; i++) {
                for (unsigned int j = 0; j < size; j++) {
                    if (i!=j) {
                        for (unsigned int n: matrix[i][j]->v) {
                            thisCopy->insert(n,i,j); // <--error happens here
                        }
                    }
                }
            }
            return thisCopy;
        }
}

以某种方式调整矩阵大小时，Edge结构的v字段是否被错误地重新分配？我尝试查看this answer，但就我而言，v只是一个向量，所以我不知道为什么这对我适用。