我正在实现一个双重链接列表类,它存储“桶”(节点),每个包含预定义数量的字符。每个存储桶存储指向下一个和前一个存储桶的指针,列表类(BucketString)存储指向头部存储桶的指针。我正在编译使用g ++抛出错误
terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
make: *** [run] Aborted (core dumped)
每当我运行代码并在列表中添加一个字符串时,使用以下add方法(包含在我的bucket类中),并在需要时从列表类自己的方法中调用。
代码:
std::size_t bucketSizeB;
int filled;
char* str;
Bucket* next;
Bucket* prev;
Bucket::Bucket() : bucketSizeB(7), str(new char[7]), next(NULL), prev(NULL), filled(0)
{}
Bucket::Bucket(std::size_t bucketSizeB_) : bucketSizeB(bucketSizeB_), str(new char[bucketSizeB]), next(NULL), prev (NULL), filled(0)
{}
Bucket::Bucket(const Bucket& rhs) : bucketSizeB(rhs.bucketSizeB), next(rhs.next), prev(rhs.prev), filled(rhs.filled)
{
for (int i = 0 ; i < (int) bucketSizeB ; i++)
{
str[i] = rhs.str[i];
}
}
void Bucket::add(std::string line)
{
int diff = bucketSizeB - filled; //if the bucket is already partially filled
std::string tmp = line.substr(0, diff);
for (std::size_t i = 0 ; i < tmp.length() ; i++)
{
str[filled] = line[i];
++filled;
}
if (line.length() > bucketSizeB)
{
next = new Bucket(bucketSizeB);
next->prev = this;
next->add(line.substr(diff, line.length()-diff));
}
}
Bucket::~Bucket()
{
if (prev)
{
if (next)
{
prev->next = next;
}
else
{
prev->next = NULL;
}
}
if (next)
{
if (prev)
{
next->prev = prev;
}
else
{
next->prev = NULL;
}
}
delete [] Bucket::str;
}
当抛出错误时,将从'list'类成员方法append调用add方法,其工作方式如下:
void BucketString::append (std::string& line)
{
length += line.length(); //Just a way to store the length of the string stored in this BucketString object
if (!head) //If the head node pointer is currently null, create a new head pointer
{
head = new Bucket(bucketSize);
}
Bucket* tmp = head;
while (tmp->next) //Finds the tail node
{
tmp = tmp->next;
}
tmp->add(line); //Calls the Bucket add function on the tail node
}
存储桶类的头文件是:
#include <cstddef>
#include <string>
#include <iostream>
#ifndef BUCKET_H_
#define BUCKET_H_
namespace RBNWES001
{
class Bucket
{
public:
//Special members and overloaded constructor
Bucket(void);
Bucket(std::size_t);
Bucket(const Bucket&);
~Bucket();
//Copy Assignment not included because it's not needed, I'm the only one who is gonna use this code! :)
//Add method
void add(std::string);
int filled;
char* str;
Bucket* next;
Bucket* prev;
std::size_t bucketSizeB;
};
}
#endif
答案 0 :(得分:5)
1)您可以使用try / catch块阻止终止。
2)听起来这是在执行程序时发生的。它听起来像“make”自动执行程序。正确的吗?
3)如果是这样,你想查看一个调试器,并确定它崩溃的确切行。
4)我怀疑如果你追踪代码,你会看到“diff”,“bucketSizeB”和/或“filled”中的一个或多个变得非常大(或者是负数)。这将是一个错误:)你可以轻松修复 - 一旦你找到它。
5)以下是关于GDB的好教程,如果它恰好是一个方便的调试器:
答案 1 :(得分:5)
这样做:在我的Bucket(std::size_t bucketSizeB)
构造函数中,str
的初始化程序应该从str(new char[bucketSizeB]
更改为str(new char[bucketSizeB_])
(即使用传递给cosntructor的参数而不是使用bucketSizeB变量)。