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嘿即時得到我認爲有從閱讀其他職位，香港專業教育學院與複製ofstream的變量做了一個錯誤試圖改變C++編譯器錯誤不能訪問類中聲明私有成員「的std :: basic_ios <_Elem，_Traits>」
std::ofstream outfil;
到
std::ofstream & outfil;
，但我得到的錯誤
reference value "outfil" requires an initializer
代碼：
#include <algorithm>
#include <fstream>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>
#include <vector>
#include <cstdlib>
std::vector<double> GetValues_n(const std::vector<std::string>& src, int start, int end)
{
std::vector<double> ret;
for(int i = start; i <= end; ++i)
{
ret.push_back(std::strtod(src[i].c_str(), nullptr));
}
return ret;
}
std::vector<int> GetValues_c(const std::vector<std::string>& src, int start, int end)
{
std::vector<int> ret;
for(int i = start; i <= end; ++i)
{
ret.push_back(std::atoi(src[i].c_str()));
}
return ret;
}
std::vector<double> polycentre(const std::vector<double>& x,const std::vector<double>& y,size_t ID)
{
std::vector<double> C(3, 0);
std::vector<double> x1(x.size(),0);
std::vector<double> y1(y.size(),0);
size_t sizx = x.size();
size_t sizy = y.size();
if(sizy != sizx)
{
std::cerr << "polycentre inputs not equal length";
}
double x0 = x[0];
double y0 = y[0];
for(int aa = 1; aa < sizx; ++aa)
{
if(x[aa] < x0){x0 = x[aa];}
if(y[aa] < y0){y0 = y[aa];}
}
double A = 0.0;
double B = 0.0;
for(size_t aa = 0; aa < sizx; ++aa)
{
x1[aa] = x[aa] - x0;
y1[aa] = y[aa] - x0;
if(aa != sizx-1)
{
A = A + (x1[aa]*y1[aa+1] - x1[aa+1]*y1[aa]);
B = B + ((x1[aa]+x1[aa+1])*(x1[aa]*y1[aa-1]-x1[aa-1]*y1[aa]));
}
else if(aa == sizx-1)
{
A = A + (x1[aa] - y1[aa]);
B = B + ((x1[aa]+1)*(x1[aa]*1-1*y1[aa]));
}
}
A = A*0.5;
C[0] = ID;
C[1] = ((1/6/A)*B)+x0;
C[2] = ((1/6/A)*B)+y0;
return C;
}
template <typename T>
void PrintValues(const std::string& title, std::vector<std::vector<T>>& v, std::ofstream outfil)
{
if(outfil.is_open())
{
outfil << "ID,X,Y,Z \n";
std::cout << title << std::endl;
for(size_t line = 0; line < v.size(); ++line)
{
for(size_t val = 0; val < v[line].size(); ++val)
{
std::cout << v[line][val] << " ";
outfil << v[line][val] << ",";
}
outfil << "\n";
std::cout << std::endl;
}
std::cout << std::endl;
}
}
int main(int argc, char* argv[])
{
std::ofstream & outfil;
if (argc < 2)
{
std::cerr << argv[0] << " needs to get input file (2dm)" << std::endl;
}
else if (argc == 3)
{
outfil.open(argv[2]);
}
else
{
outfil.open(std::string(argv[1]) + ".csv");
}
std::vector<std::vector<std::string>> values;
std::ifstream fin(argv[1]);
for (std::string line; std::getline(fin, line);)
{
std::istringstream in(line);
values.push_back(
std::vector<std::string>(std::istream_iterator<std::string>(in),
std::istream_iterator<std::string>()));
}
std::vector<std::vector<int>> cells;
std::vector<std::vector<double>> nodes;
for (size_t i = 0; i < values.size(); ++i)
{
if(values[i][0] == "E3T")
{
cells.push_back(GetValues_c(values[i], 1, 5));
}
else if(values[i][0] == "E4Q")
{
cells.push_back(GetValues_c(values[i], 1, 6));
}
else if(values[i][0] == "ND")
{
nodes.push_back(GetValues_n(values[i], 1, 4));
}
}
std::vector<std::vector<double>> cell_centres;
for (size_t aa = 0; aa < cells.size(); ++aa)
{
if(cells[aa].size() == 5)
{
std::vector<double> xs;
xs.at(0) = nodes[cells[aa][1] - 1][1];
xs.at(1) = nodes[cells[aa][2] - 1][1];
xs.at(2) = nodes[cells[aa][3] - 1][1];
std::vector<double> ys;
ys.at(0) = nodes[cells[aa][1] - 1][2];
ys.at(1) = nodes[cells[aa][2] - 1][2];
ys.at(2) = nodes[cells[aa][3] - 1][2];
cell_centres.push_back(polycentre(xs,ys,aa+1));
}
else if(cells[aa].size() == 6)
{
std::vector<double> xs;
xs.at(0) = nodes[cells[aa][1] - 1][1];
xs.at(1) = nodes[cells[aa][2] - 1][1];
xs.at(2) = nodes[cells[aa][3] - 1][1];
xs.at(3) = nodes[cells[aa][4] - 1][1];
std::vector<double> ys;
ys.at(0) = nodes[cells[aa][1] - 1][2];
ys.at(1) = nodes[cells[aa][2] - 1][2];
ys.at(2) = nodes[cells[aa][3] - 1][2];
ys.at(3) = nodes[cells[aa][4] - 1][2];
cell_centres.push_back(polycentre(xs,ys,aa+1));
}
}
PrintValues("Cell Centres", cell_centres, outfil);
//PrintValues("Cells", cells, outfil);
//PrintValues("Nodes", nodes, outfil);
return 0;
}
和錯誤是：
1>------ Build started: Project: cell_centres_v2, Configuration: Debug Win32 ------
1> main.cpp
1>c:\users\********\documents\visual studio 2010\projects\cell_centres_v2\cell_centres_v2\main.cpp(43): warning C4018: '<' : signed/unsigned mismatch
1>c:\program files (x86)\microsoft visual studio 10.0\vc\include\fstream(1116): error C2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\ios(176) : see declaration of 'std::basic_ios<_Elem,_Traits>::basic_ios'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
1> This diagnostic occurred in the compiler generated function 'std::basic_ofstream<_Elem,_Traits>::basic_ofstream(const std::basic_ofstream<_Elem,_Traits> &)'
1> with
1> [
1> _Elem=char,
1> _Traits=std::char_traits<char>
1> ]
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
非常感謝。