C++ lvalue references cannot bind to rvalues: detect the error with post-increment operands. #include <iostream.h> int main() { int m = 2, n = 6; int &x = m++; int &y = n++; m = x++; x = m++; n = y++; y = n++; cout << m << " " << n; return 0; }

Introduction / Context:
This question targets reference binding rules in C++. Non-const lvalue references (int&) cannot bind to temporaries (rvalues). Using a post-increment expression as a reference initializer creates such a temporary, triggering a compilation error.

Given Data / Assumptions:

• int &x = m++; and int &y = n++;
• Post-increment yields rvalues (the old values), not lvalues.
• Classic iostream.h headers do not affect this rule.

Concept / Approach:
The initializer for x is m++ which is an rvalue; a non-const lvalue reference cannot bind to it. The same applies to y. Modern C++ permits binding a const reference to a temporary, but not a non-const reference. Therefore compilation fails before any runtime output is possible.

Step-by-Step Solution:

Verification / Alternative check:
Replacing with const int &x = m++; and const int &y = n++; would compile (binding to temporaries allowed for const refs), though subsequent ++ uses would fail due to constness.

Why Other Options Are Wrong:

• All numeric outputs assume successful compilation and execution.

Common Pitfalls:
Assuming references can bind to any expression; confusing lvalues and rvalues; forgetting the special rule for const references to temporaries.

Final Answer:
It will result in a compile time error.