所以我想要做的是寫一個類作爲其數據成員的模板類。這是我功課的一部分。如何使模板類成爲另一個類的數據成員?
到目前爲止,這是我:
letter_frequencies.h
#include "ltr_freq_pair.h"
#include "darray.h"
class letter_frequencies
{
private:
darray<letterFrequencyStruct> array;
public:
letter_frequencies();
void outputFrequencies();
};
letter_frequencies.cpp
#include <iostream>
#include "letter_frequencies.h"
letter_frequencies::letter_frequencies()
{}
void letter_frequencies::outputFrequencies()
{
for(int index = 0; index < 26; index ++)
{
std::cout << "\n" << array[index].letter;
std::cout << " " << array[index].frequency;
}
}
一切編譯,但是一旦我運行它,它有這樣的錯誤:
a.out: darray.cpp:44: T& darray<T>::operator[](unsigned int) [with T = letterFrequencyStruct]: Assertion 'index < used' failed. Abort (core dumped)
的代碼片段,我嘗試使用這個類是:
//Check if Class Works
letter_frequencies array;
array.outputFrequencies();
眼下,darray工作得很好,程序不正是我需要做的,但其中一個要求是有一個名爲letter_frequency的類與數據成員darray<structTypename> name
,這就是爲什麼我在這個第一個地方忙碌。
此外,我將如何使課堂呼籲darray明確的構造函數?我想大小設置爲26
darray.h
#ifndef DARRAY_H
#define DARRAY_H
#include <iostream>
template <typename T>
class darray
{
public:
//Constructors
darray();
darray(const darray&);
explicit darray(unsigned);
//Destructor
~darray();
//Constant Members
unsigned size() const {return used;}
unsigned capacity() const {return cap;}
//Modification Members
T& operator [] (unsigned);
void pop_back();
void push_back(const T&);
const T* find(const T&) const;
void resize(unsigned);
//Operators
T& operator = (const darray&);
bool operator == (const darray&) const;
//Friends
template <typename X>
friend std::ostream& operator << (std::ostream& output, const darray<X>& array);
private:
T* arr;
unsigned used, cap;
};
template <typename X>
std::ostream& operator << (std::ostream& output, const darray<X>& array)
{
for(int index = 0; index < array.size; index++)
{
output << index << array[index];
}
return output;
}
#include "darray.cpp"
#endif
我斗膽說'darray'未初始化/相應調整。你的'letter_frequencies'類的構造函數是空的,你很快就會訪問'darray'。也許如果你發佈了'darray.h'源文件? – Massa
@Massa對不起,剛添加它。 – user3062299