Advanced · Module 10 · Lesson 3 of 6
Casts With Intent: static, dynamic, const and reinterpret
Convert with the narrowest cast that states intent, check polymorphic downcasts at runtime, and remove const only from values that began life mutable.
By the end you can
- Choose static, dynamic, const or reinterpret cast for a given conversion
- Check dynamic downcasts for null and explain the polymorphic requirement
- Apply const cast safely to non-const origins without undefined behavior
Builds on The Rule of Five and When to Default It.
01 · A question first
A base pointer points at a derived object and the program needs the derived operation. One conversion checks the type at runtime and can fail cleanly. Another trusts the programmer and can corrupt state. Which cast states the check, and which one hides it?
Make a guess before you read on.
02 · The idea
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What's inside
- Start with the problem
- How the idea works
- Why it is correct
- What it costs
- Const cast and undefined behavior: the narrow boundary
- A const_cast safety demonstration
- A checklist for picking a cast
- Original cast examples
03 · Practice
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