C++ miscellaneous
practice.

#include <iostream>
using namespace std;
int main ()
{
    int i;
    cout << "Please enter an integer value: ";
    cin >> i + 4;
    return 0;
}

#include<iostream>
#include <fstream>
using namespace std;
int main () 
{
    ofstream outfile ("test.txt");
    for (int n = 0; n < 100; n++)
    {
        outfile << n;
        outfile.flush();
    }
    cout << "Done";
    outfile.close();
    return 0;
}

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() 
{
    string s = "spaces in text";
    s.erase(remove(s.begin(), s.end(), ' ' ), s.end() ) ;
    cout << s << endl;
}

#include<iostream>
#include<any>
using namespace std;
int main()
{
	int a = 5;
	any var = a;
	cout<<var<<endl;
	return 0;
}

#include <stdexcept>
#include <limits>
#include <iostream>
using namespace std;
void MyFunc(char c)
{
    if (c < numeric_limits<char>::max())
        return invalid_argument;
}
int main()
{
    try
    {
        MyFunc(256);
    }
    catch(invalid_argument& e)
    {
        cerr << e.what() << endl;
        return -1;
    }
    return 0;
}

#include <iostream>
using namespace std;
template <class T>
class A
{
    public:
    A(int a): x(a) {}
    protected:
    int x;
};
template <class T>
class B: public A<char>
{
    public:
    B(): A<char>::A(100) 
    {
        cout << x * 2 << endl;
    }
};
int main()
{
    B<char> test;
    return 0;
}

#include <iostream>
using namespace std;  
template<int n> 
struct funStruct
{
    static const int val = 2*funStruct<n-1>::val;
};
 
template<> 
struct funStruct<0>
{
    static const int val = 1 ;
};
 
int main()
{
    cout << funStruct<10>::val << endl;
    return 0;
}

#include <iostream>
using namespace std;
void square (int *x)
{
    *x = (*x + 1) * (*x);
}
int main ( )
{
    int num = 10;
    square(&num);
    cout << num;
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main ()
{
    srand (time(NULL));
    printf ("Random number: %d\n", rand() % 100);
    srand (1);
    return 0;
}