c++ - *迭代器导致段错误

Question

我正在尝试遍历一个列表。以下是一些声明:

list<CG1_Edge*> ActiveEdges;
list<CG1_Edge*>::iterator ActiveEdgeIterator;

有时，这段代码会在第 2 行出现段错误:

for (this->ActiveEdgeIterator = this->ActiveEdges.begin(); this->ActiveEdgeIterator != this->ActiveEdges.end(); ++this->ActiveEdgeIterator) {
    CG1_Edge* currentEdge = *this->ActiveEdgeIterator;
    if (currentEdge->y_up < y)
        this->ActiveEdges.erase(this->ActiveEdgeIterator);
}

这可能导致段错误的常见原因有哪些？

Answer 1

你应该使用类似的东西:

for (this->ActiveEdgeIterator = this->ActiveEdges.begin(); this->ActiveEdgeIterator != this->ActiveEdges.end(); ) {
    CG1_Edge* currentEdge = *this->ActiveEdgeIterator;
    if (currentEdge->y_up < y)
        this->ActiveEdgeIterator = this->ActiveEdges.erase(this->ActiveEdgeIterator);
    else
        ++this->ActiveEdgeIterator;
}

因为 erase 返回一个定位在下一个元素的迭代器。

(注意:将迭代器作为成员看起来很奇怪。)