Output for Struct is not turning out right!

[hershize]

Below is the output:

Input the first numerator: 1
Input the first denominator: 2
Is the fraction positive? (Y or N): Y
Input the second numerator: 1
Input the second denominator: 2
Is the fraction positive? (Y or N): N
Result is: 1/4

I want 1/4 to become a negative with a "-" in front if it. I keep getting positives when I indicate that one of the fraction is a negative. Any help is appreciated. Thanks!

  #include <cstdlib>
#include <iostream>

using namespace std;

struct fraction
{
    int num;
    int denom;
    bool positive;
};

struct fraction fracMult(struct fraction &f1, struct fraction &f2, struct fraction &fresult);

int main()
{
    fraction f1, f2, fresult;
    char tempchar;
    
    cout << "Input the first numerator: ";
    cin >> f1.num;
    cout << "Input the first denominator: ";
    cin >> f1.denom;
    cout << "Is the fraction positive? (Y or N): ";
    cin >> tempchar;
    
    if (tempchar = 'Y')
    {
        f1.positive = true;
    }
    else
    {
        f1.positive = false;
    }
    
    cout << "Input the second numerator: ";
    cin >> f2.num;
    cout << "Input the second denominator: ";
    cin >> f2.denom;
    cout << "Is the fraction positive? (Y or N): ";
    cin >> tempchar;
    
    if (tempchar = 'Y')
    {
        f2.positive = true;
    }
    else
    {
        f2.positive = false;
    }
    
    fracMult(f1, f2, fresult);
    
    cout << "Result is: ";
    if (fresult.positive = false)
    {
        cout << "-";
    }
    cout << fresult.num << "/" << fresult.denom << endl;
    
    return 0;
}

struct fraction fracMult(struct fraction &f1, struct fraction &f2, struct fraction &fresult)
{
    fresult.num = f1.num * f2.num;
    fresult.denom = f1.denom * f2.denom;
    
    if (f1.positive == f2.positive)
    {
        fresult.positive = true;
    }
    else
    {
        fresult.positive = false;
    }
    
    return fresult;
}

[long double main]

All of your if statements should have == instead of =.