C ++通过对象创建的奇怪分段错误 [英] C++ strange segmentation fault by object creation

问题描述

我有一个奇怪的问题，通过启动一个类对象。
问题是奇怪，但不容易重现。但我会尝试给一个指示的例子。
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) {
      ...
   }
};

有时候如果我用下面的方式启动对象，我会通过初始化得到分割错误。 >

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，那么它是OK ..

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行给出一个编译器错误。

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

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

我应该如何正确启动一个对象，特别是当它有默认构造函数和那些有参数。

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

 解决方案 

推荐答案

c $ c> FooClass foo1（）;

FooClass foo1();

不会创建类型为FooClass的对象，而是声明一个名为foo1（）返回FooClass。删除括号以创建实例，如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segmmentation错误可能与你的析构函数，我们看不到，这不会被调用你的第二个例子泄漏。

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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