对象创建引起的 C++ 奇怪的分段错误

C++ strange segmentation fault by object creation(对象创建引起的 C++ 奇怪的分段错误)

问题描述

通过启动类对象，我遇到了一个奇怪的问题.这个问题很奇怪，也不容易重现.但是，我将尝试举一个说明性的例子.我有继承类.

I have a strange problem by initiating a class object. The problem is as strange as well not easily reproducible. However I will try to give an indicating example. I have inheritance classes.

class BarClass {
public:
   BarClass() {
      ...
   }
   BarClass(int i, int j) {
      ...
   }
   void doSomething() { ... }
};
class FooClass : public BarClass {
public:
   FooClass() {
   }
   FooClass(int i, int j) : BarClass(i,j) {
      ...
   }
};

有时如果我用以下方式启动对象，我会通过初始化得到分段错误错误.

Sometime if I initiate objects with following manner, I will get segmentation fault error by initialization.

FooClass foo1;
foo1.doSomething();
FooClass foo2(10, 20);
foo2.doSomething();

如果我使用显式指针new，那么没关系..

If I use explicit pointer new, then it is OK..

FooClass *foo1= new FooClass();
foo1->doSomething();
FooClass foo2(10, 20);
foo2.doSomething();

以下代码将在第 2 行给我一个编译器错误.

The following code will give me a compiler error on line 2.

FooClass foo1();
foo1.doSomething();
FooClass foo2(10, 20);
foo2.doSomething();

我应该如何正确地初始化一个对象，尤其是当它有默认构造函数和带有参数的时候.

how should I properly initiate a object, especially when it has default constructor and those with arguments.

推荐答案

你的上一期先...

FooClass foo1();

不会创建 FooClass 类型的对象，而是声明一个名为 foo1() 的函数，该函数不接受任何参数并返回一个 FooClass.删除括号以创建实例，就像您在第一个代码示例中所做的那样.

does not create an object of type FooClass but declares a function called foo1() that takes no parameters and returns a FooClass. Remove the parentheses to create the instance as you did in the first code sample.

为什么你得到一个分段错误可能与你的析构函数有关，我们看不到，这在你的第二个泄漏示例中没有被调用.

why you get a segmmentation fault may have something to do with your destructor which we can't see, and this doesn't get invoked in your second example which leaks.

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