Capturing uncertainty 2

Understanding C++ type casting and undefined behaviour

This is a hard C++ question that tests your ability to trace through code involving type conversions, pointer arithmetic, and the subtle rules governing value representation. It rewards deep familiarity with the C++ standard and how different casting operations interact with memory layout.

To solve problems like this, you need to reason carefully about what happens when you reinterpret data across type boundaries, how compilers handle conversions between fundamentally different representations, and which operations invoke undefined or implementation-defined behaviour. The question demands that you move beyond surface-level syntax and understand the formal semantics underneath.

• Static vs. reinterpret casting and their guarantees
• Sign extension and two's complement representation
• Pointer-to-integer and integer-to-pointer conversions
• Implementation-defined vs. undefined behaviour in the standard