我写了一个文件读取器/写入器，代码还没有完成。
#include <iostream>
#include <fstream>
#include <string>
const std::string path_to_data = "\\data";
const std::string level_file = path_to_data+"\\level_file.lev";
typedef std::string (*f_read)(std::ifstream& fin,const std::string& level_file,int line_num);
typedef std::string (*f_write)(std::ofstream& fout,const std::string& level_file, std::string& what_to_write,int line_num);
typedef std::string (*pt_f_manger)(f_read,f_write);
inline bool is_empty(std::ifstream& pFile){return pFile.peek() == std::ifstream::traits_type::eof();}
std::string file_manger(f_read,f_write);
std::string read_file(std::ifstream& fin,const std::string& level_file,int line_num);
std::string write_file(std::ofstream& fout,const std::string& level_file,std::string what_to_write, int line_num);
std::string error_handler(std::string error_type,pt_f_manger f_manger);
int main()
{
std::string error = file_manger(read_file,write_file);
std::cout<<error<<"\n";
std::cin.get();
std::cin.get();
return 0;
}
std::string file_manger(f_read f_input,f_write f_output)
{
std::string good = "good";
std::string error = "error";
std::ifstream fin;
std::ofstream fout;
std::string test = "test";
std::string output = f_output(fout,level_file,test,0);
std::string input = f_input(fin,level_file,0);
if (output != "good")
return error;
if (input != "good")
return error;
return good;
}
std::string write_file(std::ofstream& fout,const std::string& level_file, std::string& what_to_write,int line_num)
{
const char* level_filec = level_file.c_str();
std::ifstream fin;
fin.open(level_filec);
if (fin.is_open())
return "failed to open "+level_file;
if (is_empty(fin))
{
fin.close();
fout.open(level_filec);
if (!fout.is_open())
return "failed to open "+level_file;
fout<<what_to_write;
fout.close();
return "good";
}
int i = 0;
int num = 0;
char ch;
while (fin.good() && i != line_num)
{
fin.get(ch);
if (ch == '\n')
++num;
++i;
}
int pos = fin.tellg();
fin.close();
fout.open(level_filec,std::ios_base::in);
if (!fout.is_open())
return "failed to open "+level_file;
fout.seekp(pos);
fout<<what_to_write;
fout.close();
return "good";
}
std::string read_file(std::ifstream& fin,const std::string& level_file,int line_num)
{
const char* level_filec = level_file.c_str();
std::string read;
fin.open(level_filec);
if (fin.is_open())
return "failed to open "+level_file;
if (is_empty(fin))
{
fin.close();
return "file is empty";
}
int i = 0;
int num = 0;
char ch;
while (fin.good() && i != line_num)
{
fin.get(ch);
if (ch == '\n')
++num;
++i;
}
std::getline(fin,read);
return read;
}
std::string error_handler(std::string error_type,pt_f_manger f_manger)//work in progress
{
return "good";
}
我得到这个错误
C:\Users\john\Documents\main.cpp||在函数'int main()':| C:\Users\john\Documents\main.cpp|25|错误：从 'std::string (*) (std::ofstream&, const string&, std::string, int) {aka std::basic_string (*) (std::basic_ofstream&, const std::basic_string&, std::basic_string, int)}' 到 'f_write {aka std::basic_string (*)(std::basic_ofstream&, const std::basic_string&, std: :basic_string&, int)}' [-fpermissive]| C:\Users\john\Documents\main.cpp|17|错误：初始化 'std::string file_manger(f_read, f_write)' [-fpermissive]| 的参数 2 ||=== 构建完成：2 个错误，0 个警告（0 分钟，0 秒）===|
我正在使用代码::块。