cpp-flashcards/.learning/cpp-pointers-and-references/syllabus.md

C++ Pointers and References — Syllabus

Overview

Master C++ indirection mechanisms from declaration syntax through move semantics. Emphasis on building correct mental models, real-world usage patterns, and surviving interview questions about pointers and references.

Prerequisites

• Basic C++ syntax (variables, functions, structs/classes)
• Understanding of stack vs heap (conceptual)

Learning Objectives

By completion you will be able to:

• Read and write any pointer/reference declaration confidently
• Explain the difference between &/* in declarations vs expressions
• Use const-correctness with pointers and references correctly
• Understand ownership semantics and choose the right smart pointer
• Handle move semantics and forwarding references
• Answer common interview questions on pointers and references

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Phase 1: Foundations — Declaration Syntax & Mental Models

• & and * in declarations vs expressions — the two contexts
• Does * / & bind to the type or the variable? (C++ parsing rules)
• Multiple declarations on one line: int *a, b — what is b?
• Pointers: what they are (address), what they hold, how to dereference
• References: what they are (alias), how they differ from pointers
• Pointer vs reference: when to use which (guidelines)
• Null pointers: NULL vs nullptr vs 0

Teaching Milestone: Explain the "declaration follows use" principle to a beginner.

Phase 2: const Correctness & Function Signatures

• const int* vs int* const vs const int* const
• const int& — why it's the default parameter style
• Top-level const vs low-level const
• East const vs West const style
• Passing by value vs by reference vs by pointer — tradeoffs
• Return by reference: when safe, when dangerous
• Pointer arithmetic basics

Teaching Milestone: Read a complex function signature and explain what each parameter accepts and whether it can be modified.

Phase 3: Ownership & Smart Pointers

• Raw pointer ownership problems (leaks, double free, dangling)
• RAII principle
• std::unique_ptr — exclusive ownership
• std::shared_ptr — shared ownership and reference counting
• std::weak_ptr — breaking cycles
• Choosing the right smart pointer (decision tree)
• std::make_unique / std::make_shared — why prefer them

Teaching Milestone: Refactor a raw-pointer design to use smart pointers and explain your choices.

Phase 4: Move Semantics & Advanced References

• Lvalue vs rvalue — what are they really
• Lvalue references (T&) vs rvalue references (T&&)
• std::move — what it does and doesn't do
• Move constructors and move assignment
• Reference collapsing rules
• Forwarding references (T&& in templates)
• std::forward — perfect forwarding
• Common interview traps and trick questions

Teaching Milestone: Explain why std::move doesn't actually move anything.

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Resources

• cppreference.com — authoritative reference
• "Effective Modern C++" by Scott Meyers — Items 1-6, 23-26
• Herb Sutter's GotW articles on const correctness

Success Criteria

• Can read any declaration with *, &, const and explain it
• Can choose between pointer, reference, and smart pointer for any use case
• Can explain move semantics without hand-waving
• Can spot pointer/reference bugs in code review