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smitty007 (48)
Write your question here.
I'm trying to work out the bugs in this program and feel as though I have it ready to go. I'm encountering a problem in the form of an error on line 233. I've done some preliminary research and am wondering if my compiler is not up to date? How do I fix this problem through my coding syntax? I'm using CodeBlocks. Is the problem originating from the tostring command? Thank you for the help!
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  #include <iostream>
#include <fstream>
#include <cstdlib>
#include <cstdio>
#include <sstream>

using namespace std;

struct Fraction
{
int numerator;
int denominator;
};

struct FractionArray
{
Fraction *fractions; //this will point to an array of fractions
int nFractions; //this will contain the number of elements in the array
};

bool readDataAndShowFractions(string filename, FractionArray &fractions);
bool readDataIntoArray(ifstream *infile, Fraction fractions[], int size);
Fraction newFraction(int num, int denom);
void printFractions(FractionArray fractions);
void reduce(Fraction &f);
int gcd(int x, int y);

//functions to perform fraction arithmetic
Fraction add(Fraction op1, Fraction op2);
Fraction subtract(Fraction op1, Fraction op2);
Fraction multiply(Fraction op1, Fraction op2);
Fraction divide(Fraction op1, Fraction op2);
double getDecimal(Fraction);

//used to convert an integer to a string
//to_string() is defined in the latest version of C++ but is not supported by older compilers
string tostring(int number);
string tostring(Fraction f);

int main(int argc, char *argv[])
{
//create two structures, one for each array
FractionArray fractions1;
FractionArray fractions2;

bool success;
//initialize and output the first array of Fraction structures
success = readDataAndShowFractions("fractiondata1.txt", fractions1);

if (!success)
    {
    cout << "Fraction array could not be constructed from fractiondata1.txt" << endl;
    exit(-1);
    }

//initialize and output the second array of Fraction structures
success = readDataAndShowFractions("fractiondata2.txt", fractions2);

if (!success)
    {
    cout << "Fraction array could not be constructed from fractiondata2.txt" << endl;
    exit(-1);
    }

//make sure the arrays are of equal size

if (fractions1.nFractions != fractions2.nFractions )
    {
    cout << "Fraction arrays are not the same size" << endl;
    exit(-1);
    }

//loop through the Fraction arrays and output the results of
//adding the fractions at each position
for (int i = 0; i < fractions1.nFractions; i++)
    {
    Fraction result = add(fractions1.fractions[i],
    fractions2.fractions[i]);
    cout << tostring(fractions1.fractions[i]) << " + "
    << tostring(fractions2.fractions[i]) << " = "
    << tostring(result) << endl;
    }

// subtract
for (int i = 0; i < fractions1.nFractions; i++)
    {
    Fraction result = subtract(fractions1.fractions[i],
    fractions2.fractions[i]);
    cout << tostring(fractions1.fractions[i]) << " + "
    << tostring(fractions2.fractions[i]) << " = "
    << tostring(result) << endl;
    }

// multiply
for (int i = 0; i < fractions1.nFractions; i++)
    {
    Fraction result = multiply(fractions1.fractions[i],
    fractions2.fractions[i]);
    cout << tostring(fractions1.fractions[i]) << " + "
    << tostring(fractions2.fractions[i]) << " = "
    << tostring(result) << endl;
    }

// divide
for (int i = 0; i < fractions1.nFractions; i++)
    {
    Fraction result = divide(fractions1.fractions[i],
    fractions2.fractions[i]);
    cout << tostring(fractions1.fractions[i]) << " + "
    << tostring(fractions2.fractions[i]) << " = "
    << tostring(result) << endl;
    }

// decimal value fraction 1
for (int i = 0; i < fractions1.nFractions; i++)
    {
    cout << tostring(fractions1.fractions[i]) << " = "<<getDecimal(fractions1.fractions[i])<<endl;
    }

// decimal value fraction 2
for (int i = 0; i < fractions2.nFractions; i++)
    {
    cout << tostring(fractions2.fractions[i]) << " = "<<getDecimal(fractions2.fractions[i])<<endl;
    }
cin.get();
return 0;
}

//adds the two fractions together, creates a new Fraction from the result and
//returns it
Fraction add(Fraction op1, Fraction op2)
{
int num1;
int num2;
int denom;
denom = op1.denominator * op2.denominator;
num1 = (denom / op1.denominator) * op1.numerator;
num2 = (denom / op2.denominator) * op2.numerator;
Fraction result;
result.numerator = num1 + num2;
result.denominator = denom;
reduce(result);
return result;
}
//subtract the two fractions together, creates a new Fraction from the result and
//returns it
Fraction subtract(Fraction op1, Fraction op2)
{
int num1;
int num2;
int denom;
denom = op1.denominator * op2.denominator;
num1 = (denom / op1.denominator) * op1.numerator;
num2 = (denom / op2.denominator) * op2.numerator;
Fraction result;
result.numerator = num1 - num2;
result.denominator = denom;
reduce(result);
return result;
}
//multiply the two fractions together, creates a new Fraction from the result and
//returns it
Fraction multiply(Fraction op1, Fraction op2)
{
int num;
int denom;
denom = op1.denominator * op2.denominator;
num = op1.numerator * op2.numerator;
Fraction result;
result.numerator = num;
result.denominator = denom;
reduce(result);
return result;
}

//multiply the two fractions together, creates a new Fraction from the result and
//returns it
Fraction divide(Fraction op1, Fraction op2)
{
int num;
int denom;
denom = op1.denominator * op2.numerator;
num = op1.numerator * op2.denominator;
Fraction result;
result.numerator = num;
result.denominator = denom;
reduce(result);
return result;
}
// function to get decimal value
double getDecimal(Fraction f){
return (double)f.numerator/(double)f.denominator;
}
//reduces the given fraction
void reduce(Fraction &f)
{
int factor = gcd(f.numerator, f.denominator);
f.numerator = f.numerator / factor;
f.denominator = f.denominator / factor;
}
//returns the greatest common denominator of two values
int gcd (int x, int y)
{
if (y == 0)
return x;
else
return gcd(y, x % y);
}

Fraction newFraction(int num, int denom)
{
Fraction f;
f.numerator = num;
f.denominator = denom;
return f;
}

/*
Reads fraction data from the given file into the array
defined in the given structure.
Returns true if successful, false if any errors were encountered.
*/
bool readDataAndShowFractions(string filename, FractionArray &fractions)
{
//read the size to make the array and create it
ifstream *infile;
infile = new ifstream(filename, ios::in);
if (!infile->is_open())
return false;
//read the number of values into the struct variable and make
//sure it is not 0
if (*infile >> fractions.nFractions && fractions.nFractions > 0)
    {
    fractions.fractions = new Fraction[fractions.nFractions];
    readDataIntoArray(infile, fractions.fractions, fractions.nFractions);
    }
infile->close();
printFractions(fractions);
return true;
}
/* Given a pointer to an open file and an array, reads size data from the file
and populates the array.*/
bool readDataIntoArray(ifstream *infile, Fraction fractions[], int size)
{
int numerator;
int denominator;
for (int i = 0; i < size; i++)
    {
    *infile >> numerator;
    if (infile->eof())
    return false;
    *infile >> denominator;
    if (infile->eof())
    return false;
    //Add a structure for the new fraction
    fractions[i] = newFraction(numerator, denominator);
    }
return true;
}
void printFractions(FractionArray fractions)
{
cout << "Fraction data from array" << endl;
for (int i = 0; i < fractions.nFractions; i++)
{
cout << tostring(fractions.fractions[i]) << endl;
}
cout << endl;
}

string tostring(int number)
{
//const int size = sizeof(int) * 4;
//char buf[size + 1];
stringstream ss;
ss << number;
//sprintf_l(buf, "%d", number);
//return string(buf);
return ss.str();
}
string tostring(Fraction f)
{
string num = tostring(f.numerator);
string denom = tostring(f.denominator);
return num + "\\" + denom;
}
helios (17562)
What's the error?
smitty007 (48)
The error says: no matching function for call to 'std: : basic_ifstream<char>: :
helios (17562)
That can't be whole error. Look more carefully at the compiler output.
smitty007 (48)
From what I can tell, the error has to do with the function:
bool readDataAndShowFractions (string filename, FractionArray &fractions)
mbozzi (3932)
Last edited on
smitty007 (48)
The error occurs in line 227 when I try to compile this program:

no matching function for call to 'std::basic_ifstream<char>::basic_ifstream(std...)

smitty007 (48)
I was able to figure out where my code was going wrong.
I had to change some syntax in line 227 to ifstream file (filename.c_str());
Thank you for the help!
Chervil (7320)
Why are you using a pointer and new without delete in that function?

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ifstream *infile;
infile = new ifstream(filename, ios::in);
if (!infile->is_open())
return false;


would be better like this, change -> to . where appropriate
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    ifstream infile( filename.c_str() );
    if (!infile)
        return false;
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