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In next C++ standard x10 you will be able to do same as in Java or C#

Yes but no use, It will create temporary object.

Correct, this can be done.

Simply calling the constructor would create a temporary object, which will be destroyed on the very next line (i.e. the scope of that object would be the line it is getting created).

This is covered in C++ faq . Here's the link
c++-faq-lite/ctors.html#faq-10.3

What is the use case for this scenarios when would we do this ?

Pre C++11 we can't call a different constructor of the same class , however in C++11, this is allowed which are called delegate constructors.

class A {
   private:
       int n;
  public:

     A( int numb) { n=number;}

    A() : A(42) {}
}

#include <iostream>
using namespace std;

class base{
};

class der : public base {
public:
	der() : base()
	{
		//base();
		cout<<"hello "<<endl;
	}
};

int main()
{
	der d;
	return 0;
}