The Narrowing Guard

What this C++ type-narrowing interview question tests

This is a medium-difficulty C++ language-knowledge question that probes your understanding of implicit type conversions and how compilers handle floating-point precision across different numeric types. It is commonly used to assess whether a candidate has developed intuition about C++'s type system beyond surface-level syntax.

To answer correctly, you need to trace through the conversion rules when values move between float and double, and understand how precision is gained or lost in the process. The question rewards careful reasoning about what happens at the machine level when data is cast, stored, or compared across types of different sizes.

• Implicit vs. explicit type conversion
• Floating-point representation and precision loss
• Compiler behavior and undefined behavior boundaries
• Platform-specific assumptions about sizeof