C++ Error no match for operator << when trying to display a list

Question

I don't know what's wrong with this code, I'm a c++ newbie, could someone help me fix it? I've been having issues with this for some time and I don't know how to fix it. I've tried messing with the code, but to no success. Anyone know what's wrong with this?

#include <iostream>
#include <cstdlib>
#include <iomanip>
#include <list>

using namespace std;

void rising(double T[], int n)
{
    double pom;
    for (int j=n-1;j>0;j--)
    for (int i=0;i<j;i++)
    if (T[i]>T[i+1])
    {
        pom=T[i];
        T[i]=T[i+1];
        T[i+1]=pom;
    }
}
void lowering(double T[], int n)
{
    double pom;
    for (int j=n-1;j>0;j--)
    for (int i=0;i<j;i++)
    if (T[i]<T[i+1])
    {
        pom=T[i];
        T[i]=T[i+1];
        T[i+1]=pom;
    }
}
void show(double T[], int n)
{
    for(int i=0; i<n; i++)
    cout<<T[i]<<setw(3);
    cout<<endl;
}
int main()
{
    double tablica[]={2, 12, 3, 4, 5, 4, 7, 8, 9, 9, 0};
    cout<<"elementy tablicy to: "<<show(tablica,11)<<endl;
    cout<<"elementy tablicy posortowane rosnaco: "<<rising(tablica,11)<<endl;
    cout<<"elementy tablicy posortowane malejaco: "<<lowering(tablica,11)<<endl;
    cin.get();
    cin.ignore();
    return 0;
}

Answer 1

The problem is here:

 cout<<"elementy tablicy to: "<<show(tablica,11)<<endl;

<<show(tablica,11)

to function show does not return any value (its return type is void),

you can simply call the function to perform its print:

int main()
{
    double tablica[] = { 2, 12, 3, 4, 5, 4, 7, 8, 9, 9, 0 };
    cout << "elementy tablicy to: ";
    show(tablica, 11);

Answer 2

Your functions have void return type, there is nothing << operator can do with them, fortunately you already have the functions to do what you want, you just have to call them in the correct fashion and order:

int main()
{
    double tablica[]={2, 12, 3, 4, 5, 4, 7, 8, 9, 9, 0};
    cout<<"elementy tablicy to: ";
    show(tablica,11);
    rising(tablica,11);
    cout<<"elementy tablicy posortowane rosnaco: ";
    show(tablica,11);
    lowering(tablica,11);
    cout<<"elementy tablicy posortowane malejaco: ";
    show(tablica,11);
    cin.get();
    return 0;
}