我有一个头文件,其中一个函数是:
template <class Pclass, class Pfunc1, class Pfunc2> //Capable of multiple outputs per call
int view_recordT(Pclass Object_1, char Compare_char, char* file_1, Pfunc1 show_tablular, Pfunc2 get_compare_char) { //Search function to find records
int currID, records_read;
bool run=false;
ifstream fin;
fin.open(file_1, ios::binary); //Opens the file again
if(!fin) { //Checks whether the file file_1 exists or not
cout<<"File not found!";
return(-1);
}
while(fin>>currID && fin.read((char*)& Object_1, sizeof(Object_1))) //Reads a record into stream until it can't
if(Object_1.get_compare_char() == Compare_char) {
records_read++;
cout<<endl; AddColumn(currID,7); Object_1.show_tablular();
run=true;
}
fin.close();
if(run==false) //Returns a false flag (0) if records not found
return int(run);
return records_read; //Otherwise, the number of records read is returned
}
注意: bool是一个枚举,因为TurboC ++不支持布尔值,true / false。 enum bool { false, true }
由于我的愚蠢学校,我一直在使用TurboC ++,我们甚至没有教过模板,这就是为什么我要问这个,可能是愚蠢的问题。
class Test_Class {
int int_member;
char char_member[20], group_ID;
float float_member;
static int currID; //Static Var for Record Keeping in Files
public:
Test_Class();
void enter();
void show_tablular();
char get_group_id();
static int ret_ID() { //Repeative calls are recorded & count is returned.
return ++currID;
}
};
int Test_Class::currID = 0;
void main() {
clrscr();
Test_Class Object, Object1;
char file[20];
strcpy(file,"lib_Test.dat");
int run, records_read=0;
char group_ID;
cout<<"Enter the Group ID to be searched for: ";
cin>>group_ID;
run = view_recordT(Object, group_ID, file, &Test_Class::show_tablular, &Test_Class::get_group_id);
if(run == false)
cout<<"\nRecord not found!";
cout<<"\n Total of "<<records_read<<" records have been read!";
getch();
}
这里的目标是将一个Object传递给view_recordT()以及来自test.cpp的类方法的地址,以便view_recordT()可以执行语句,就好像它是Test_Class的一个成员一样。 但我得到一个错误:
get_compare_var()不是Test_Class
的成员
如何修改view_recordT()函数,使其完全独立于它用于读取文件的类?
答案 0 :(得分:1)
该代码中存在很多错误(部分是turbo-c ++的错误),例如main
必须返回int
和if(run = false)
应该是if (run == false)
和各种非标准功能。
修复大部分I can reproduce your error后。查找pointer to member function的语法。是的,语法很奇怪。在您的情况下,正确的语法是
if((Object_1.*get_compare_char)() == Compare_char) {
更改该行之后,编译器会发出更多问题警告,例如records_read
未初始化。考虑使用真正的编译器进行开发,然后尝试turbo-c ++是否能够编译它。