尝试返回类的类型,但错误的模板参数
问题描述:
我总共有5个函数重载&,+, - ,*和/只有一个类,只有一个动态创建的数组与arrSize作为私人成员。我也使用模板来普及类和它的重载函数。在我遇到的5个函数的每一个函数中,我都得到错误无效使用模板名称'SmartArray'而没有参数列表。这里是我的功能:尝试返回类的类型,但错误的模板参数
/* function description: overrides the & operator. Lets us concatenate two arrays together.
parameters: const SmartArray& numArray is the right-hand array being concatenated to the left-hand array.
return value: void
*/
template <class ArrType>
SmartArray<ArrType>& SmartArray::operator&(const SmartArray& numArray) const{
SmartArray concatenate(arrSize+numArray.length()); // creating object with array large enough to hold both arrays.
for(int i=0; i<arrSize; i++) // putting left-hand array into concatenated array
concatenate.elements[i] = elements[i];
for(int i=arrSize; i<arrSize+numArray.length(); i++) // puts in right-hand array elements second
concatenate.elements[i] = numArray.elements[i-arrSize];
return concatenate;
}
/* function description: overrides + operator. Lets us add the contents of two arrays together.
parameters: const SmartArray& numArray is the right-hand array being added to the left-hand array.
return value: SmartArray
*/
template <class ArrType>
SmartArray SmartArray::operator+(const SmartArray& numArray) const{
SmartArray added; // initializes array to hold added arrays
if(arrSize > numArray.length()){ // checks which array is larger, then creates new array with the larger size
SmartArray added(arrSize);
for(int i=0; i<numArray.length(); i++)
added.elements[i] += numArray.elements[i];
for(int i=numArray.length(); i<arrSize; i++)
added.elements[i] = numArray.elements[i];
}else if(arrSize <= numArray.length()){
SmartArray added(numArray.length());
for(int i=0; i<arrSize; i++)
added.elements[i] += numArray.elements[i];
for(int i=arrSize; i<numArray.length(); i++)
added.elements[i] = numArray.elements[i];
}
return added;
}
/* function description: overrides + operator. Lets us subtract the contents of two arrays together.
parameters: const SmartArray& numArray is the right-hand array being subtracted to the left-hand array.
return value: SmartArray
*/
template <class ArrType>
SmartArray SmartArray::operator-(const SmartArray& numArray) const{
SmartArray subtracted; // initializes array to hold subtracted arrays
if(arrSize > numArray.length()){ // checks which array is larger, then creates new array with the larger size
SmartArray subtracted(arrSize);
for(int i=0; i<numArray.length(); i++)
subtracted.elements[i] -= numArray.elements[i];
for(int i=numArray.length(); i<arrSize; i++)
subtracted.elements[i] = numArray.elements[i];
}else if(arrSize <= numArray.length()){
SmartArray subtracted(numArray.length());
for(int i=0; i<arrSize; i++)
subtracted.elements[i] -= numArray.elements[i];
for(int i=arrSize; i<numArray.length(); i++)
subtracted.elements[i] = numArray.elements[i];
}
return subtracted;
}
/* function description: overrides + operator. Lets us multiply the contents of two arrays together.
parameters: const SmartArray& numArray is the right-hand array being multiplied to the left-hand array.
return value: SmartArray
*/
template <class ArrType>
SmartArray SmartArray::operator*(const SmartArray& numArray) const{
SmartArray multiplied; // initializes array to hold multiplied arrays
if(arrSize > numArray.length()){ // checks which array is larger, then creates new array with the larger size
SmartArray multiplied(arrSize);
for(int i=0; i<numArray.length(); i++)
multiplied.elements[i] *= numArray.elements[i];
for(int i=numArray.length(); i<arrSize; i++)
multiplied.elements[i] = numArray.elements[i];
}else if(arrSize <= numArray.length()){
SmartArray multiplied(numArray.length());
for(int i=0; i<arrSize; i++)
multiplied.elements[i] *= numArray.elements[i];
for(int i=arrSize; i<numArray.length(); i++)
multiplied.elements[i] = numArray.elements[i];
}
return multiplied;
}
/* function description: overrides + operator. Lets us divide the contents of two arrays together.
parameters: const SmartArray& numArray is the right-hand array being divided to the left-hand array.
return value: SmartArray
*/
template <class ArrType>
SmartArray SmartArray::operator/(const SmartArray& numArray) const{
SmartArray divided; // initializes array to hold divided arrays
if(arrSize > numArray.length()){ // checks which array is larger, then creates new array with the larger size
SmartArray divided(arrSize);
for(int i=0; i<numArray.length(); i++)
divided.elements[i] /= numArray.elements[i];
for(int i=numArray.length(); i<arrSize; i++)
divided.elements[i] = numArray.elements[i];
}else if(arrSize <= numArray.length()){
SmartArray divided(numArray.length());
for(int i=0; i<arrSize; i++)
divided.elements[i] /= numArray.elements[i];
for(int i=arrSize; i<numArray.length(); i++)
divided.elements[i] = numArray.elements[i];
}
return divided;
}
随着第一个功能,我尝试使用
SmartArray<ArrType>& SmartArray::.....
,但我得到了错误“‘模板类的SmartArray’不使用模板参数。”
答
无处不在您使用SmartArray
类型,您需要包含要使用的模板类型。例如,
template <class ArrType>
SmartArray<ArrType> SmartArray<ArrType>::operator&(const SmartArray<ArrType>& numArray) const{
SmartArray<ArrType> concatenate(arrSize+numArray.length());
注意添加<ArrType>
到numArray
在参数列表中的声明和concatenate
局部变量。我也从函数返回类型中删除了&
,因为你不想返回一个对局部变量的引用。
您必须对其他功能进行类似的更改。
这工作!但是,为了让你知道,我还需要在每个双冒号(::)前添加“”。 –