COMS W4995 C++ Deep Dive for C Programmers

Fall 2025

• COMS 4995-007: Mon & Wed 5:40-6:55pm, 750 CEPSR (Costa Engineering Commons)

• Two synchronous and in-person exams:

  • Exam 1: Wednesday October 22, 5:40p - 7:10p
  • Exam 2: Wednesday December 17, 4:10p - 7:00p

  There are no make-up or alternate exams. If you cannot make any of those exams, please take the course next time.

• Instructor: Hans J. Montero

• Hans & TA office hours: calendar

• Anonymous feedback form

Course essentials

• OVERVIEW AND LOGISTICS
• REQUIRED READING: ACADEMIC HONESTY POLICIES
• Linux Programming Environment – same as COMS 3157
• Jae’s Git Tutorial – same as COMS 3157
• Lab Workflow
• Helpful Guides

Important Dates

Date	Assignment
F 9/19	Lab 1 due
Su 10/5	Lab 2 due
F 10/17	Lab 3 due
W 10/22	Exam 1
F 11/14	Lab 4 due
M 12/8	Lab 5 due
W 12/17	Exam 2

Course Schedule

Lecture 1: W 9/3

Course overview and logistics

• OVERVIEW AND LOGISTICS
  • 00-overview

• Assignments:

  1. Subscribe to c2cpp@lists.cs.columbia.edu – see L00 above

  2. Read the following two documents:
     • http://www.cs.columbia.edu/education/honesty
     • http://www.cs.columbia.edu/~jae/honesty.html

  3. HW0 due Fri 9/5, 11:59pm

     Send an email to Hans and Jae containing:

     • To: hans@cs.columbia.edu, jae@cs.columbia.edu
     • Subject: “[c2cpp] hw0-UNI” – without quotes, sole space before hw0, UNI replaced with your actual UNI in lowercase
     • Your name, major & school program, year – e.g., Hans Montero, Computer Science, Columbia Engineering, class of 2021
     • Your pledge – see http://www.cs.columbia.edu/~jae/honesty.html
     • CS classes taken and/or other programming background
     • Optionally anything else you want to let us know
     • Optionally attach a picture of you, but please reduce image file size to about 100KB

C to C++ (c2cpp)

• Lecture: 01-c2cpp
  • Compiling & linking C++ code with Makefile
  • Introduction to string, iostream, namespace
• Source code:
  • Makefile, hello.cpp

Lecture 2: M 9/8

Basic-4 in C++

• Lecture: 02-basic4
  • Member functions
  • Constructors and destructors
  • Stack allocations and heap allocations
• Source code: Makefile, basic4.cpp

Lecture 3: W 9/10

Basic-4 in C++ (continued)

• Lecture: 02-basic4
  • heap allocation of arrays
  • passing by value vs. passing by reference
  • const member function
  • three cases of copy construction
  • copy elision
• Source code: Makefile, basic4.cpp

Lecture 4: M 9/15

Basic-4 in C++ (continued)

• Lecture: 02-basic4
  • copy assignment
  • compiler-generated basic4
• Source code: Makefile, basic4.cpp

MyString class

• Lecture: 03-mystring
  • Motivation
  • Source code overview
    • mystring.h vs. mystring.cpp
    • Makefile and test drivers
  • MyString constructor
• Source code: MyString class & test drivers

Lecture 5: W 9/17

MyString class (continued)

• Lecture: 03-mystring
  • Basic-4 of MyString class
  • Inlining member functions
  • operator+
• Source code: MyString class & test drivers

Lecture 6: M 9/22

MyString class (continued)

• Lecture: 03-mystring
  • put-to & get-from operators
  • operator[]
  • Exception handling
• Source code: MyString class & test drivers

Function template

• Lecture: 04-function-template
  • Defining a function template
  • Template specialization
  • Template compilation model
• Source code: Max() function template & test code

Lecture 7: W 9/24

Dynamically growable array

• Lecture: 05-dynamically-growable-array
  • IntArray class & code walkthrough
  • Time complexity of push_back()
  • Strong exception guarantee
  • Member initializer list
• Source code: Makefile, intarray1.cpp

Move semantics

• Lecture: 06-move-semantics
  • Motivation: returning large objects efficiently
  • Implementing move constructor
  • Copy elision eliminates move constructor calls
• Source code: Makefile, intarray2.cpp

Lecture 8: M 9/29

Move semantics (continued)

• Lecture: 06-move-semantics
  • Review of move constructor: motivation and implementation
  • L-value vs. r-value references
  • Implementing move assignment
  • Casting to rvalue reference
  • std::move()
• Source code: Makefile, intarray2.cpp, rvalue-test.cpp

Vec class template

• Lecture: 07-vec-class-template
  • Turning IntArray into a class template
  • Value semantics of STL containers
• Source code: Makefile, vec1.cpp,

Lecture 9: W 10/1

Vec class template (continued)

• Lecture: 07-vec-class-template
  • Stack & heap diagram of Vec<MyString>
  • Placement new()
  • Strong exception guarantee revisited
• Source code: Makefile, vec2.cpp, vec3.cpp, mystring.h, mystring.cpp

Inheritance and Polymorphism

• Lecture: 08-inheritance
  • Inheritance basics
  • Memory layout of derived classes
• Source code: Makefile, inherit1.cpp

Lecture 10: M 10/6

Inheritance and Polymorphism (continued)

• Lecture: 08-inheritance
  • Inheritance basics (review)
  • Memory layout of derived classes (review)
  • Static binding vs. dynamic binding
  • Virtual function table (vtable)
  • Multiple inheritance object layout
  • static_cast
• Source code: Makefile, inherit1.cpp, inherit2.cpp

Lecture 11: W 10/8

Inheritance and Polymorphism (continued)

• Lecture: 08-inheritance
  • Multiple inheritance without virtual functions (review)
  • static_cast (review)
  • Multiple inheritance with virtual functions
  • The diamond problem
  • Virtual inheritance
  • Order of construction & destruction
  • Pure virtual functions & abstract class
  • Virtual destructor
• Source code: Makefile, inherit2.cpp inherit3.cpp inherit4.cpp inherit5.cpp

I/O streams

• Lecture: 09-io-streams
  • I/O Stream Library class hierarchy
  • I/O manipulator
• Source code: Makefile, io1.cpp,

Lecture 12: M 10/13

I/O streams (continued)

• Lecture: 09-io-streams
  • I/O Stream Library class hierarchy (review)
  • I/O manipulator (review)
  • I/O state
  • Recovering from I/O failure
  • Mixing C and C++ I/O
  • I/O of user-defined structure
  • String streams
  • File streams

• Source code: Makefile, io1.cpp, io2.cpp, io3.cpp,

• Sample input files: good, malformed

Lecture 13: W 10/15

STL Sequence Containers

• Lecture: 10-sequence-containers
  • Arrays in C++
  • std::array
  • std::vector
  • std::deque
  • std::list
  • std::forward_list
• Source code: Makefile, stl.cpp

Lecture 14: M 10/20

Iterators

• Lecture: 11-iterators
  • For_Each() template function
  • begin() & end()
  • const_iterator
  • iterator and range-for loop
  • Subtleties in For_Each() implementation
    • (b != e) vs. (b < e)
    • ++b vs. b++
• Source code: Makefile, iterator1.cpp

Lecture 15: W 10/22

Exam 1

• Coverage:
  • Labs 1, 2, and 3
  • Lecture notes 1-9 (up to and including I/O streams)
    • Type alias (using syntax) from lecture note 10
  • Sample exams
  • All ANN emails

Lecture 16: M 10/27

Iterators (continued)

• Lecture: 11-iterators
  • std::initializer_list<T>
  • Iterator adapters
  • Stream iterators
  • Iterator categories
• Source code: Makefile, iterator2.cpp

Lecture 17: M 10/27

Associative containers

• Lecture: 12-associative-containers
  • std::map & std::unordered_map
  • std::multimap & std::unordered_multimap
  • std::set & variants
• Source code: Makefile, words1.cpp, words2.cpp

Template metaprogramming

• Lecture: 13-template-metaprogramming
  • std::distance
  • Tag dispatching
• Source code: Makefile, mydistance.cpp

No class on M 11/3 – Fall Break

Lecture 18: W 11/5

Template metaprogramming (continued)

• Lecture: 13-template-metaprogramming
  • Tag dispatching (review)
  • SFINAE
  • if constexpr
• Source code: Makefile, mydistance.cpp

Lecture 18: M 11/10

Template metaprogramming (continued)

• Lecture: 13-template-metaprogramming
  • if constexpr (review)
  • Concepts
• Source code: Makefile, mydistance.cpp

Functional programming in C++

• Lecture: 14-functional-programming
  • Function objects (aka functors)
  • Stateless vs. stateful functors
  • std::bind_front() & std::bind()
• Source code: Makefile, functor.cpp

Lecture 19: W 11/12

Functional programming in C++ (continued)

• Lecture: 14-functional-programming
  • Lambda expressions and closures
  • Ranges
• Source code: Makefile, functor.cpp

Random number generator

• Lecture: 15-rng
  • Random number generator in C vs. C++
• Source code: Makefile, rand1.cpp, rand2.cpp

Lecture 20: M 11/17

Random number generator (continued)

• Lecture: 15-rng
  • Random number generator in C vs. C++ (review)
  • Mersenne Twister engine (review)
  • Normal distribution
  • Danger of narrowing conversions
  • Stateful functors
  • Very stateful functors
• Source code: Makefile, rand1.cpp, rand2.cpp

Lecture 21: W 11/19

Value categories and forwarding reference

• Lecture: 16-fwd-ref-variadic
  • l-value vs. r-value
  • Forwarding reference
  • Perfect forwarding
• Source code: Makefile, values.cpp, fwd-ref.cpp

Lecture 22: M 11/24

Value categories and forwarding reference (continued)

• Lecture: 16-fwd-ref-variadic
  • Perfect forwarding (review)
  • std::forward<T>()
• Source code: Makefile, fwd-ref.cpp

Variadic templates

• Lecture: 16-fwd-ref-variadic
  • Variadic template using recursion
  • Forwarding parameter pack
  • Fold expression
• Source code: Makefile, variadic.cpp

No class on W 11/26 – Thanksgiving Break

Lecture 23: M 12/1

Smart Pointers

• Lecture: 17-smart-pointers
  • Introduction to smart pointer
  • auto revisited
  • SmartPtr<T> implementation
  • MakeSmartPtr<T> function template
  • shared_ptr<T> and make_shared<T>()
  • make_shared<T>() combines allocations
  • shared_ptr to an array and custom deleter
• Source code: Makefile, sharedptr.h, sharedptr1.cpp, sharedptr2.cpp

Guest Lecture: Tuesday 12/2

Swift and C++ Interoperability, by John Hui

Time: 10:10am - 11:25am

Location: CSB 453 (Traub Conference Room)

Abstract:

C++ interoperability is an actively evolving feature of the Swift programming language, and allows large C++ projects to gradually incorporate memory-safe Swift code without compromising C++’s expressiveness at the language boundary. In this talk, I will explain how Swift interoperates with C++ and why this matters for modern software development. I’ll introduce Swift through the lens of C++ interoperation, starting from what the two languages have in common, and build toward the practical and design challenges of bridging them.

Bio:

John Hui is a compiler engineer on the C Languages & Libraries team at Apple, where he works on C++ interoperability in Swift. Prior to Apple, John completed his undergraduate (CC’18) and graduate (MS’19, PhD’24) studies at Columbia University. For his doctoral research, he worked with Prof. Stephen Edwards on a software programming model for real-time embedded systems.

Lecture 24: W 12/3

Smart Pointers (continued)

• Lecture: 17-smart-pointers
  • Aliasing
  • weak_ptr
  • unique_ptr
• Source code: Makefile, sharedptr2.cpp, uniqueptr.cpp

(Bonus) Introduction to concurrency

• Topics covered:
  • Introduction to threads
  • C pthread API
  • False sharing & cache conscious programming
  • Mutex
• Source code: Makefile, pthread.cpp

Lecture 25: M 12/8

(Bonus) Introduction to concurrency (continued)

• Topics covered:
  • C++ threads: std::thread and std::mutex
  • RAII for threads: std::jthread and std::scoped_lock
  • Condition variable
• Source code: Makefile, concur.cpp, cond-var.cpp

Course wrap-up

• Slides: xx-wrap-up

Exam 2: W 12/17

Exam 2

• Logistics:
  • W 12/17, 4:10p - 7p
  • CEPSR 750 (our usual classroom)
  • Length: 2hr (but you can use the full 2hr 50min period)
• Coverage:
  • Labs 1-5
  • Lecture notes 1-17
    • Skip over I/O state and multiple/virtual inheritance object layout and vtable details
    • Lecture note 18 (concurrency) is out of scope
  • Our Exam 1
  • All sample exams
  • All ANN emails

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Last updated: 2025-12-8