C++ Practice

Master RAII, move semantics, templates, and the STL.

Language Essentials

Concept	Details
Memory Model	RAII, smart pointers (`unique_ptr`, `shared_ptr`), stack preference
Type System	Strong static typing, templates, concepts (C++20), `auto`
Error Handling	Exceptions (use judiciously), `std::expected` (C++23), `std::optional`
Concurrency	`std::thread`, `std::async`, `std::atomic`, coroutines (C++20)
Build	`cmake`, `g++`/`clang++`, modules (C++20), header-only libraries
Standard	C++20 (prefer) or C++23

Key Idioms

RAII everywhere — destructors for cleanup, no manual delete
Move semantics — std::move, rvalue references, rule of five/zero
SFINAE / Concepts — constrain templates at compile time
Range-based for with structured bindings
std::variant + std::visit for sum types
CRTP (Curiously Recurring Template Pattern) for static polymorphism
constexpr for compile-time computation

Reference Documentation

cppreference.com — authoritative reference
ISO C++ FAQ — common questions
A Tour of C++ (Stroustrup, 3rd ed.) — concise modern overview
Effective Modern C++ (Scott Meyers) — essential C++11/14 patterns
C++ Core Guidelines — free, maintained by Stroustrup & Sutter

Practising these

practice/bin/ol list  build cpp          # which of these have references yet
practice/bin/ol start build cpp 01       # clone it stubbed into .scratchpad/
practice/bin/ol check build cpp 01       # run it; exit code is the verdict
practice/bin/ol diff  build cpp 01       # your attempt against the reference

Exercises are ordered by concept, not by difficulty, so pick by the stars rather than by the number. An exercise listed below with no reference yet is a row in this table and nothing more; see the practice path for how the harness works.

Exercises

#	Exercise	Concepts	Difficulty
01	`Vector<T>` (like `std::vector`)	Templates, move semantics, allocator awareness	⭐⭐⭐
02	`UniquePtr<T>`	RAII, move-only types, custom deleters	⭐⭐
04	Compile-time matrix (`constexpr`)	`constexpr`, template metaprogramming	⭐⭐⭐
05	Thread-safe queue	`std::mutex`, `std::condition_variable`, move semantics	⭐⭐⭐
06	Expression template (lazy eval)	CRTP, operator overloading, zero-cost abstractions	⭐⭐⭐⭐
07	Coroutine generator	C++20 coroutines, `co_yield`, lazy sequences	⭐⭐⭐⭐
08	`std::function` clone	Type erasure, small buffer optimization	⭐⭐⭐⭐
09	Graph with concepts	C++20 concepts, ranges, BFS/DFS	⭐⭐⭐
10	Memory pool allocator	Custom allocator, placement new, alignment	⭐⭐⭐⭐

Exercise 03 (hash map) is consolidated into the course: six hash maps across the drills became two course modules, ds.02 (Swiss table, C) and ds.05 (Robin Hood, Rust), whose chapters live in Systems Data Structures.