XCode Linker错误，简单的C ++函数

Question

我有一个用xcode编写的程序，并且只有骨架可以正常运行。 我去添加一些代码，当我添加三个函数时，它们都是私有的，其中两个都内嵌到.h和.cpp中。 当我去编译时，我得到了链接器错误，因为上帝知道原因。 我正在制作函数的类也继承自一个结构，但我不认为这应该是一个问题。 病态发布下面的代码。 （这个项目有很多东西，所以我不能发布所有内容）

#ifndef HEAP_SORT_H
#define HEAP_SORT_H

#include "Interfaces02.h"
#include "CountedInteger.h"

class HeapSort : public IHeapSort {
public:
HeapSort();
virtual ~HeapSort();
virtual void buildHeap(std::vector<CountedInteger>& vector);
virtual void sortHeap(std::vector<CountedInteger>& vector);
private:
virtual unsigned int l(int i);
virtual unsigned int r(int i);
virtual void fixDown(std::vector<CountedInteger>& vector, int p);
};

#endif


#include "HeapSort.h"
#include "CountedInteger.h"

HeapSort::HeapSort()
{
}

HeapSort::~HeapSort()
{
}

void HeapSort::buildHeap(std::vector<CountedInteger>& vector)
{    

int i = ((int) vector.size()) - 1;
for(; i > 1; i--)
{
    fixDown(vector, i);
}


}

void HeapSort::sortHeap(std::vector<CountedInteger>& vector)
{
}

inline unsigned int l(int i)
{
return ((i*2)+1);
}

inline unsigned int r(int i)
{
   return ((i*2)+2);
}

void fixDown(std::vector<CountedInteger>& vector, int p)
{

int largest;

if(l(p) <= vector.size() && vector[l(p)] > vector[p])
   {
       largest = l(p);
   }
   else
   {
       largest = p;
   }
if(r(p) <= vector.size() && vector[r(p)] > vector[p])
   {
       largest = r(p);
   }
if(largest != p)
{
    CountedInteger temp = vector[largest];
    vector[largest] = vector[p];
    vector[p] = temp;
    fixDown(vector, largest);
}


}

这是它给我的错误：

Undefined symbols for architecture x86_64:
"HeapSort::l(int)", referenced from:
vtable for HeapSort in HeapSort.o
  "HeapSort::r(int)", referenced from:
  vtable for HeapSort in HeapSort.o
  "HeapSort::fixDown(std::vector<CountedInteger,std::allocator<CountedInteger>>&,int)", 
 referenced from:
  vtable for HeapSort in HeapSort.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Answer 1

您没有实现：

virtual unsigned int l(int i);
virtual unsigned int r(int i);
virtual void fixDown(std::vector<CountedInteger>& vector, int p);

您忘记了在实现文件中限定这些方法。

inline unsigned int l(int i)

与...不同

inline unsigned int HeapSort::l(int i)

就像现在一样，它们只是在该翻译单元中定义的自由函数。