我正在學習C++類,對於我最近的作業,我必須創建一個Box
類。總的來說,這個任務實際上是在公園裏散步,但我在我應該創建的重載插入算子方面遇到了一些麻煩。按照標準,插入運算符在box.h
中聲明,並在box.cpp
中定義。在Box
類中,我有一個print(std::ostream &) const
函數。所有重載插入操作符都會調用提供給操作員的std::ostream &
上的print
函數。相關代碼:當我使用我的重載insertopm(<<)運算符時,爲什麼會得到SIGSEGV?
void Box::print(std::ostream &outStream) const { // The java in me loves abstraction
if ((_boxType == BoxType::FILLED) || (_boxType == BoxType::HOLLOW))
_printFilledOrHollow(outStream);
else if (_boxType == BoxType::CHECKERED)
_printCheckered(outStream);
}
void Box::_printFilledOrHollow(std::ostream &outStream) const {
if (_width > 1) {
outStream << string(_width, 'x') << endl;
for (int i = 0; i < (_height - 2); i++) { //works for everything but 1
if (_boxType == Box::FILLED)
outStream << string(_width, 'x') << endl;
else
outStream << "x" << string((_width - 2), ' ') << "x" << endl;
}
outStream << string(_width, 'x') << endl;
} else
outStream << "x" << endl; //which is what this is for
}
void Box::_printCheckered(std::ostream &outStream) const {
if (_boxType == Box::CHECKERED) {
for (int row = 0; row < _height; row++) {
for (int col = 0; col < _width; col++) {
if ((row % 2) == 0) { // if even column
if (col % 2 == 0)
outStream << "x";
else
outStream << " ";
} else {
if ((col % 2) != 0)
outStream << "x";
else
outStream << " ";
}
}
cout << endl;
}
}
}
std::ostream &operator<<(std::ostream &outStream, const Box &rhs) {
rhs.print(outStream);
}
現在,這是真正奇怪的部分。如果我在cout << "";
到Box::print
函數的末尾添加一些內容,它會按預期完成,而不使用SIGSEGV。我完全被這個難住了,希望你們至少可以告訴我爲什麼會發生這種事。如果有必要的話,我會在Box::Print
的末尾用cout << ""
來打開它,但我真的更願意處理這個錯誤。謝謝!
啓用編譯器警告(例如使用'-Wall'),您將立即發現問題。 – user4407569