C++ vs. C# - a Checklist from a C++ Programmers Point of View
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I realize for most of you this is probably old news. I have been taking a first look at C# a little while ago, because I wanted to know if it is worth looking into, and because I am thinking about polishing up my class on Parallel Programming here at the university with a little language diversification. I have taught it using POSIX Threads before, but since everyone and their grandmother seems to use Java or C# these days, throwing in a couple of examples in these languages won’t hurt. And besides, I was curious 
. Without having written a single line of code and just by reading the various guides available, I have come up with a list of differences between C# and C++ and thought you might enjoy reading it here.
And so, without any further ado and very brief, here is my list of differences between the two, sorted into three categories: things I like better in C#, things I like better in C++ and things where I could not make up my mind. The last subheading lists the resources on the net used to compile that list:
Pro C#:
- garbage collection
- array bounds checking
- huge .NET-Framework library
- types have a defined size (e.g. a long is 64Bit)
- strings are encoded in UTF/16
- autoboxing - every type can be treated as if it inherits from object
- supports constructor-chaining (one constructor can call another constructor from the same class)
- when a virtual method is called in a constructor, the method in the most derived class is used
- static constructors (run before the first instance of the class is created)
- exceptions have access to a stack trace
- advanced runtime type information and reflection
- supports variadic functions nicely
- built-in support for threads
- no need for header files and #includes
- no fall-through on switch-statements
- arithmetic operations can be checked for overflow if required
- objects must have a definite value before being used
- attributes can be attached to classes and retrieved at runtime
- no forward declarations required, classes can be arranged at will
- access to class members / functions is done only by the dot (no more -> or ::)
- conditional functions (e.g. for debugging)
- structs and classes are actually different (structs are value types, have no default constructor in general cannot be derived from)
- supports properties
- readonly members are const, but can be changed in the constructor
- finally block for exceptions
- arrays are objects
- support for anonymous functions
- supports the base keyword for calling the overridden base class
Pro C++
- better performance
- portability
- multiple inheritance
- deterministic destruction (allows RAII)
- any type can be thrown as exception (only classes derived from System.Exception in C#)
- ability to enforce const-correctness
- implicit interfaces on generics (in C#, generics must be constrained with an interface)
- offers pointers (C# only offers pointers in unsafe mode)
- support for macros
- support for global variables, functions, constants
- allows default arguments on function parameters
- STL
- supports bitfields
Where C# is just different from C++
- value types and reference types exist (struct is value-type, class is reference-type)
- value types live on the stack, reference types on the heap
- references can point to null (must not be valid)
- code is packaged in assemblies in C#
- no automatic conversion from int to bool in C#
- main-function is called Main in C#
- no semicolon after a class declaration in C#
- everything derives from object or can be treated as if
Resources
- .NET-Framework FAQ
- C# FAQ for C++ programmers
- Moving from C/C++ to C#: What to Expect
- C++ -> C#: What You Need to Know to Move from C++ to C#
- Sharp New Language: C# Offers the Power of C++ and Simplicity of Visual Basic
- C# for C++ Developers
- Die Sprache C# im Detail
Disclaimer
As you can clearly see, this is not really comprehensive. The single bullet point huge .NET-Framework library would probably fill a page at least as big as this, if it was well presented. Some categorizations may also be controversial, e.g. I see portability as a huge plus for C++, while others might not care at all (or point me to Mono). Performance is also a point where I am not so sure. I expect all the nice features of C# to bring a performance-penalty into the equation, yet if you really see this in a real-world program is an entirely different matter. But since this is by no means a comprehensive treatment of the matter anyways, you are going to have to live with it - or if you can’t, you know how to use that comment button! 
Coming to the end of this article, I have a small request: I am looking for a good book on C# development to recommend to my students (and read myself, must not forget that ), preferably one that is for people with a background in C/C++ and with content on threaded programming (because that’s what the class is all about). Browsing the reviews on the net, it appears that Programming C# is pretty good, judging from the table of contents it also covers threads, but of course I don’t know how well. Do you have any other recommendations? Or can you comment on whether the book would be suited for my purpose? Your comments are (as always) very appreciated!
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