Question

我正在写一个“PersonalVec”模板类 - 一个具有其他特质的矢量。作为模板类，我已经在.hpp中实现了所有内容，如下所示：

#ifndef PERSONALVEC_HPP_
#define PERSONALVEC_HPP_

#include <vector>
#include <iostream>
#include <string>
#include <algorithm>
#include <ctime>
#include <cstdlib>
#include <cassert>


using namespace std;

template <class T, class PrnT>
class PersonalVec{ 

 std::vecotr<T> _myVec;

public:

 typedef typename vector<T>::size_type size_type;

 PersonalVec():_myVec(){
  srand(time(NULL));
 }

 void push_back(T element){
  _myVec.push_back(element);
  if(_myVec.size()!= 0){//TODO: change to 1?!!?
   //pick a random number between 0..n-1
   int rand = rand()%_myVec.size();
   //swap
   std::swap(_myVec.at(rand), _myVec.at(_myVec.size()-1));
  }
 }

 int& operator[](size_type index){
  assert(index>=0 && index<_myVec.size());
  return _myVec.at(index);
 }

 const int& operator[](size_type index){
   assert(index>=0 && index<_myVec.size());

   const T element= _myVec.at(index);
   return element;
 }

 void erase(size_type index){
  assert(index>=0 && index<_myVec.size());
  if(index < _myVec.size()-1){
   std::swap(_myVec.at(index) , _myVec.at(_myVec.size()-1));
  }
  _myVec.pop_back();
 }

 void print(){
  for(size_type i=0; i<_myVec.size();++i){
   cout << PrnT()(_myVec.at(i))<<" ";
  }
  cout << endl;
 }

};



#endif /* PERSONALVEC_HPP_ */

我不明白我的代码有什么错误，编译器一直在喊错误：

PersonalVec.hpp:18: error: ISO C++ forbids declaration of ‘vecotr’ with no type
PersonalVec.hpp:18: error: invalid use of ‘::’
PersonalVec.hpp:18: error: expected ‘;’ before ‘<’ token
PersonalVec.hpp:43: error: ‘const int& PersonalVec<T, PrnT>::operator[](typename std::vector<T, std::allocator<_Tp1> >::size_type)’ cannot be overloaded
PersonalVec.hpp:38: error: with ‘int& PersonalVec<T, PrnT>::operator[](typename std::vector<T, std::allocator<_Tp1> >::size_type)’
PersonalVec.hpp: In member function ‘void PersonalVec<T, PrnT>::push_back(T)’:
PersonalVec.hpp:29: error: ‘_myVec’ was not declared in this scope
PersonalVec.hpp:32: error: ‘rand’ cannot be used as a function
PersonalVec.hpp: In member function ‘int& PersonalVec<T, PrnT>::operator[](typename std::vector<T, std::allocator<_Tp1> >::size_type)’:
PersonalVec.hpp:39: error: ‘_myVec’ was not declared in this scope
PersonalVec.hpp: In member function ‘const int& PersonalVec<T, PrnT>::operator[](typename std::vector<T, std::allocator<_Tp1> >::size_type)’:
PersonalVec.hpp:44: error: ‘_myVec’ was not declared in this scope
PersonalVec.hpp: In member function ‘void PersonalVec<T, PrnT>::erase(typename std::vector<T, std::allocator<_Tp1> >::size_type)’:
PersonalVec.hpp:51: error: ‘_myVec’ was not declared in this scope
PersonalVec.hpp: In member function ‘void PersonalVec<T, PrnT>::print()’:
PersonalVec.hpp:59: error: ‘_myVec’ was not declared in this scope

我真的很喜欢你的帮助，因为我真的很疯狂。

Answer 1

错字：

std::vecotr<T> _myVec;
     ^^^^^^

它应该是矢量。

Answer 2

我将您的代码放到Clang并获得

main1.cpp:18:7: error: no template named 'vecotr' in namespace 'std'; did you mean 'vector'?
 std::vecotr<T> _myVec;
 ~~~~~^~~~~~
      vector
In file included from main1.cpp:4:
In file included from /usr/include/c++/4.5.1/vector:64:
/usr/include/c++/4.5.1/bits/stl_vector.h:170:11: note: 'vector' declared here
    class vector : protected _Vector_base<_Tp, _Alloc>
          ^
main1.cpp:43:13: error: functions that differ only in their return type cannot be overloaded
 const int& operator[](size_type index){
            ^
main1.cpp:38:7: note: previous declaration is here
 int& operator[](size_type index){
      ^
main1.cpp:32:19: error: called object type 'int' is not a function or function pointer
   int rand = rand()%_myVec.size();
              ~~~~^
3 errors generated.

奇怪的编译错误 - 矢量＆amp;模板

2 个答案: