C++ Urban Myths

Question

I'm starting to write an article on what I'm calling "C++ Urban Myths" - that is, ideas and conceptions about C++ that are common but have no actual roots in reality. Some that I've come up with so far are:

TR1 is part of standard C++

• TR1 (technical Report #1) proposed a whole bunch of changes to C++. Unfortunately, it was never accepted.

It is faster to use iterators to access a vector than operator[]

• Or vice versa. All tests I've carried out indicate the two are nearly identical in performance.

The C++ Standard contains something called the STL

• It doesn't - neither "STL" nor "Standard Template Library" appear in the Standard.

I'm wondering if the SO C++ community can come up with any better ones? Ideally, they should be expressible in a single sentence, and not involve any code.

Edit: I guess I didn't make it clear enough that I was interested in myths believed by C++ developers, not misconceptions held by non-C++users. Oh well...

Answer 1

If you use new[], then delete (not delete[]) on the obtained pointer you have a memory leak.

Actually you have undefined behavior. Depending on circumstances either it just plain works or you have a heap corruption, or some other damage much worse than a memory leak, but almost never a memory leak.

Answer 2

C++ is slower than C.

Answer 3

Pre-incrementing an iterator performs significantly better than post-incrementing an iterator on modern compilers.

Answer 4

• C++ is inefficient for embedded development

• C++ is only C with Classes (see STL...)

Answer 5

Pointers are just memory addresses

• No they're not. That's why incrementing an int* doesn't advance the pointer 1 byte, but sizeof(int). It's why incrementing a pointer past allocated memory is undefined. The memory address certainly exists. The pointer does not. And of course, an implementation could map pointers to something other than memory addresses if it so chose.

And in a similar vein,

Pointers are just integers

• No they're not, that's why you can't multiply two pointers. (And of course, on hardware with segmented memory models, even memory addresses aren't just integers either)

Code written in C++ is inherently more efficient than similar code written in any other language.

Answer 6

C++ is a horrible language.

It's not the language that's horrible, its the programmers who use it in a naive way. And just as there are bad C++ programmers, you can hardly swing a dead cat without hitting bad programmers in [insert favorite language here].

C++ is an Object-Oriented language.

C++ is a multi-paradigm language. It's not object-oriented in the sense that "everything is an object" the way it is in Ruby or .NET languages. C++ supports object-oriented programming, but it also supports generic programming, functional programming, and just about any other programming paradigm you can imagine.

The STL is Object-Oriented.

According to A. Stepanov, no, it's not.

Answer 7

You have to manage the memory manually

Ok, it's a bit tricky (and somewhat provocative point of view), but using RAII you can cover almost every situation. For some extreme cases, smart pointers do the work.

Answer 8

If you make a mistake, you blow off your leg.

Most people will die when that happens, and there are far more C++ programmers than can be accounted for taking this into consideration.

Answer 9

There is a language called C/C++.

There is common misconception that if you know C++ you can easily write C code and if you know C that you can easily start writing C++ code.

These languages are so different that I would never put them one near other.

Answer 10

The STL is slow is a myth. It is often faster than writing your own containers (except for highly specialist uses like EASTL, but you certainly need an uncommon level of expertise to beat the STL), and modern compilers optimise it quite well. Occasionally you can still find fixed C arrays or containers reinvented "for efficiency," when such code may well be slower (not to mention more error-prone than the STL).

Answer 11

• STL Containers are guaranteed to be thread safe even for reading by multiple threads
  • (NB: many implementations do specifically guarantee this, including STLPort.)
• Template coding causes code bloat

Answer 12

0) In C++, you must mess around with pointers, that's old and dangerous, use C#

Gee, #include <boost/shared_ptr> or one of the like. Actually, it is often easier to produce mess in your sowonderful C#:

static void Main () {
    foo();
    bar();
}
static void foo () {
    var f = new StreamWriter ("hello.txt");
    f.Write ("hello world");
}
static void bar () {
    var f = new StreamReader ("hello.txt");
    Console.WriteLine (f.ReadToEnd ());
}

"Unhandled IOException: The process cannot access the file 'hello.txt' because it is being used by another process."

Those claims, btw, are often made by those who happen to never have heard of RAII, and about how far you can get without even smart-pointers.

1) #define SAFE_RELEASE(x) ...

without words

2) Heap-Allocation in C++ is sooo slow when compared to .net

Well, uhm, in C++, we use the stack most of the time, thanks.

3) foo=new Foo(); if (foo==NULL) {...}

See 1).

(the following are more compiler related, not sure if they really fit the topic)

Appendix A.0) Porting from MSVC to g++: found g++ bug!!!!

Answer: You must add typename there.

Answer 13

Old one, but still strong:

You need to learn C first.

Answer 14

That it's just "C-with-classes" or "Complicated-Java-without-garbage-collection".

Answer 15

Modern C++ style is MFC style

Macros are easier to use than templates

Answer 16

The whole software has to be written in C++. (No, only the optimized parts need to be written in C++).

Answer 17

The Standard allows NULL to be something other than zero, so you should not use 0.

Urban Myth!

Answer 18

C is a subset of C++. Every valid C program is also a valid C++ program.

Truth: C is not a subset of C++. Not every valid C program is also a valid C++ program.

Answer 19

Calling virtual functions is extremely slow

I've heard it many times, including here, on StackOverflow. Modern virtual tables implementations dispatch virtual function calls quite fast, with small and predicatable overhead, compared to calling usual functions. In the simplest single-inheritance case it requires just an additional access to one memory cell. I started my blog with an "article" about it.

Answer 20

Myth:

Java, C# and other higher level languages are valid alternatives to C++.

When they are, C++ was probably used for a wrong purpose to begin with. In reality, only languages like C, Ada, Forth are alternatives to C++.

Answer 21

Myth:

Everything is an object.

(I really wish it was sometimes)

Answer 22

cout << endl; is the same as cout << "\n";

They are absolutely not! cout << "\n"; simply adds a character to the output stream. cout << endl; does the same but also flushes the stream, which implies a system call, which is terribly slow.

This is IMHO one of the root cause of the C++ iostream reputation to be slow.

Answer 23

Your comment about TR1 shows something of a misunderstanding. TR1 was never intended to be a change to the base standard. TR stands for Technical Report, which means it's a separate document about whatever is specified in the associated standard -- in this case, C++.

It's not a proposed change to the base document that failed. Rather, it's (essentially) a whole new standard associated with the original one. Although it's only really intended to be useful in conjunction with the C++ standard, otherwise it has essentially the same status as the C++ standard itself -- i.e. anybody who wishes to do so can provide a conforming implementation of it.

It's also worth pointing out that nearly all of TR1 has been accepted into the draft standard for C++ 0x. The only part that's been changed to any significant degree at all is the random number generators. As such, although TR1 itself isn't (and never will be) part of the C++ standard proper, essentially the same things under slightly different names (I.e., in namespace std:: instead of std::tr1) will be part of of standard C++ relatively soon.

From a practical viewpoint, I'm hard put to figure out why anybody would care either way though. For most people, the standard is important primarily to the degree that it allows portability. From that viewpoint, TR1 is much more "standard" than support for export, for one obvious point.

Edit: As to whether TR1 and its contents will go away anytime soon, I consider it quite unlikely. The situation has been discussed before. I'd give considerable weight to Peter Becker's answer -- as current C++ 0x editor, he's probably more aware of this issue than anybody else.

Answer 24

C++ is less portable than Java.

The opposite is true.

Answer 25

C++/CLI is C++.

Truth: C++/CLI and C++ are different languages.

Answer 26

Arrays and pointers are the same thing (ok really more a C myth)

Answer 27

It is an effective debating technique to label points of disagreement "myths."

Answer 28

You have to choose a "safe subset" of C++. Don't use exceptions or templates or multiple inheritance or operator overloading or iterators or smart pointers or custom memory allocators, because those features are far too complicated for mere mortals to understand and use correctly.

Truth: The "complicated" parts of C++ are there because they can make programs simpler. Don't prohibit their use because you are not familiar with them or because you've seen them misused.

Answer 29

Myth: It is possible to use the STL correctly while in exception denial.

A few STL methods throw exceptions (e.g., std::vector::at). More importantly, the container classes expect the allocator to throw std::bad_alloc when an allocation cannot be satisfied.

If your local coding standard enforces exception denial and thus you disable exceptions in the compiler, these errors crash or corrupt data in STL calls, beyond the ability of the calling code to anticipate or handle the problem. You cannot even rely on RAII to clean up on the way out.

If you permit the compiler to generate exceptions, but disallow code from outside the STL from using try and catch, then you still cannot rely on stack-unwinding and RAII to clean up when an error is thrown from within STL. The unwinding only happens up to the highest point the exception is caught.

And, lastly, the STL containers expect the contained objects to be copyable. If you live in exception denial, what do you do if you can't guarantee success from a copy constructor? You can't throw an exception, and there's no way to signal a failure.

The design of the STL assumes the caller isn't in exception denial.

Answer 30

Exceptions are a really bad idea, slow and complicated to understand and maintain

Exceptions are a really good idea, clean and elegant an make code easier to read

EDIT: I have heard both passionately expressed. Since both cannot be true and each camp is full of smart people who care then they both must be myths

For the record I fall into the pro-exception camp.

Answer 31

C++ FQA Lite is a C++ reference

FQA Lite is an aggregation of bad-faith-formulated self-contradicting criticism of C++ written by someone with too much time on his/her hands using it to practice biased argumentations and written diarhea.

My prefered quote: http://yosefk.com/c++fqa/exceptions.html#fqa-17.4

WARNING - cyclic dependency between C++ features detected! You see, exceptions are a must in this language so that you can handle errors in all the functions which fail to look like functions, such as constructors & operators. Then it turns out that you need constructors to work with exceptions - unless each and every piece of memory you acquire is not immediately assigned to some smart pointer, your code is not exception safe. This is known as "Resource Allocation Is Initialization" (RAII) in the C++ community; it's supposed to be a good thing.

Disclaimer: Note that FQA Lite can still be useful when one needs to know the little known corners of C++... Just ignore the gratuitous bashing

Answer 32

There is such language Unmanaged C++.

This drives me crazy! There is no such thing unmanaged-C++. There is C++ and some other languages called C++/CLI. C++ is not managed.

Answer 33

C++ Exception Handling Uses more Time & Space than C

This is one misconception that prevents C++ from being used on Embedded Systems. The fact is that the equivalent exception handling in C amounts to the same time and space (perhaps a little more). The issue is that people don't write the equivalent exception handling in C; exception handling is generally ignored by C programmers.

C++ Virtual Tables occupy more time & space than C

Again, most people haven't implemented polymorphism in C. Also, programs can be written in C++ that don't use virtual functions or polymorphism.

C++, in general, uses more space and time than C.

An equivalent program written in C would use the same space or more. It may use more because some of the issues already in the C++ language would have to be added to the C language program.

C++ is not the Best Language for XXXXX project.

This comes down to price, duration, and skill sets (at least). A language that is best suited for a project (due to language features) may not be the best fit for the shop, especially when few people have experience in that language. A small team of experts in FORTRAN can develop more correct and robust software than a large team of newbies using a popular language. C++ was designed to be a generic language: it covers a wide base of requirements for many projects.

The Size of a Structure (class, etc.) is the sum of the size of the members.

People forget that compilers can add padding between members.

Class Names must begin with 'C'.

Another thing started by the MFC...

Functional Code Must Be In A Class.

C++ still supports free standing functions. Often, free standing functions are a better solution than members in classes.

The inline keyword forces the compiler to inline code.

The register keyword forces the compiler to use a register for variable.

These are only suggestions to the compiler. The compiler can ignore your suggestions.

Answer 34

C++ is low-level and requires more time to code

Low-level coding in C++ is optional. One look at the Boost C++ Libraries and you'll quickly see that C++ is capable of some very high-level constructs, without performance penalty. C++ is unique in that it "rides the fence" and provides the best of both worlds.

Many concerns with the language can be mitigated simply by taking advantage of a library or two. You can use garbage collection, if you like. Add SOCI and you have safe database access with a syntax that cannot be beat in any other mainstream language.

Give a competent coder any project and they can build it just as quickly in C++ as anything else... given the proper libraries and expertise.

Answer 35

Mangled names make it impossible to link C++ code with non-C++ code.

Truth: "Mangled names" are an implementation detail, not part of the C++ language. If your implementation makes it difficult to link C++ and non-C++ code, blame your implementation, not the language.

Answer 36

Who's your audience? If you want to convince higher-level developers (as in higher abstraction) to learn C++, you should not go straight to C++ intricacies. In a very subjective way, I'm sure C++ is a fantastic language in its possibilities of fine grain tuning, though, as a C# developer, I'm still reluctant to go C++. I'd be delighted to be convinced that the productivity/performance ratio of C++ is higher than C# or Java or (your favorite high level language) ratio. Anyway, good luck for your article.

Answer 37

There are developers who understand C++

Answer 38

"It's more straightforward to use char* than std::string."

Answer 39

Code using operator[] on std::vector instead of .at() runs faster (the latter does bounds checking). The truth: most often the compiler optimizes away any unnecessary bounds checking, making .at() just as fast. Only if the compiler cannot determine whether the index is going to be in bounds, it will keep the check.

Of course you might not get that optimization if your compiler does not optimize well or you haven't enabled optimizations.

Answer 40

C++ is faster than garbage collected languages.

This is a generalization that is widely held, and is both logically and empirically wrong. It can be faster, depending on a lot of factors, but isn't always. This is touted to justify pre-mature optimizations (such as picking C++).

Technically, this is an argument about manual memory management (or reference counting) vs. GC, not about C++, but the MYTH is perpetuated in context of C++.

Plus, C++ has general-purpose garbage collection libraries available for it :)

http://www.parashift.com/c++-faq-lite/freestore-mgmt.html#faq-16.26

Note you could expand this into "C++ is faster than higher-level languages," and all of my points can be expanded to match.

Answer 41

TR1 is part of standard C++

TR1 is a part of C++0x and it hasn't accepted yet. New MSVS and GNU GCC has particaly this extension.

Also you can use Boost library.

It is faster to use iterators to access a vector than operator[]

It depends on implementation of Standart Library

The C++ Standard contains something called the STL

Stl appears in HP and it wasn't part of standart library. Then stl became part of Standart Library of C++. But standart library also has streams, CRT, algorithms.

I very often use this name when i mean using vectors, stacks, etc.

Answer 42

1) That you know exactly what the C++ compiler is doing. Lets face it very few people do and, even though I've been writing assembler for nigh on 15 years and have a better understanding than most of what the compiler is doing under the hood, I'm STILL amazed at some of the choices a compiler makes (good and bad).

2) That a number with a ".[n]" is a float. I've had so many problems on platforms without doubles with this one. Its amazing how slow a software double to float conversion is. please remember the 'f' on the end!

3) The NIH syndrome. OK I accept this isn't juts down to C++ programmers but I've found it more with C++ programmers than anywhere else. Its fine to use someone else's code. Just make sure you use code that comes recommended or from a reputable source. Nowt worse than relying on buggy code :(

Answer 43

C++ is no longer a modern language

Actually it is syntactically most powerful imperative language.

C++ memory management model is old and inconvenient

Java was so proud to have garbage collector. In larger projects it ended up with explicit calls of methods like .dispose() (in SWT for example) and a lot of troubles with threads. In C++ you have a choice (do it manually, use memory pools, smart pointers, garbage collectors).

Arrays are evil, you should always use STL containers instead

I'm falling to pieces, when I see people using std::vector for plain arrays with known size and no other functionality than subscript access, often without forward space reservation, calling push_back(), push_back(), push_back()....

Inheritance brings some performance overhead

No it doesn't unless method is not virtual and it is not called in aid of base class.

Answer 44

You should only delete a pointer if it is not null.

Even in a destructor in which the only things being done are deleting pointers that are mebers, it is important to set each deleted pointer to null after deleting it.

memset is a good, efficient and valid way to iitialize classes and structs to an initial default zero state.

The order of initialization of members can be controlled by the order in an initializer list.

Interior classes are a nice way to keep related concepts together.

Varargs are still the best approach to output streams.

If you know C, you can easily pick up C++.

Answer 45

Myth: Since C++ is a standard it's the same everywhere

Fact: What C++ is in your environment depend on which compiler vendor and standard library you use. What compiles and runs fine in one setup might not compile or behave differently if you change some of these.

Answer 46

Myth: C++ (and C, for that matter) has macros.

Sure, these languages have things they call macros, but these things are really just text-substitutions, which can get pretty hairy and complicated.

I am currently learning Lisp, and what convinced me to do so was learning about Lisp macros: things that mold the language to what you need it to do. Of course, they can be hairy and complicated as well, but they can do a whole lot more than C/C++ "macros".

Theoretically, C++ templates help somewhat, but those are hairy and complicated things attempting to alter a hairy and complicated language. In comparison to Lisp, which is (from what I've been able to do so far) a simple, beautiful language, that has archaic, hairy and complicated ways to do things that can be done more easily in more modern languages.

In any case, Lisp has real macros, and C/C++ doesn't.

Answer 47

Perhaps more of a DailyWTF than a myth, but here goes...

The lecturer at my alma mater who taught me C++ taught our class that in this example:

for (int loop = 0; loop < 10; loop++)  {
    // Do something with loop
}

... loop would be incremented at the end of the block and in this one:

for (int loop = 0; loop < 10; ++loop)  {
    // Do something with loop
}

... loop would be incremented at the beginning.

Of course, as soon as we started using for-loops in the labs, most of us learned that this was nonsense.

However, five years after my graduation a young guy joined my team and during a code-review he explained that he was pre-incrementing his loop variable so that it was incremented at the beginning of the block. When I asked him if he was taught by [name withheld] it transpired that he was. I dread to think how many graduates left the same university with this misconception.

Answer 48

C++ is a better C

While there is great features in C++ and C is nearly a subset of C++, the base design choices are very differents. C++ is a quite high level OO programming language, even if very compiler oriented (which explains why you miss features like metaclasses but have templates). On the other side, C was born as a kind of quite low level portable assembly language.

Today as a low-level programmer I miss a really low-level language that would be object-oriented and replace C, I use C++ for such purposes but I do not believe it's C++ (there is probably one such language around I don't know of, may be go, but I'm still unsure).

A point that is largely overlooked with C vs C++ is that a C compiler is quite easy to write, while a C++ one is much more complex. When you are working really low level (think of automated parallelizers for GPU, compilers to silicium or such things) you may want to write a compiler to experiment (first hand experience, some times ago while in PHd I did it to try some features of an experimental superscalar processor). C++ is much too complex a target for such needs. The usual target is C, too bad there is no available simple OO target and you have to either stick with procedural paradigm or simulate OO programming using C.

I remember the days when C++ was a preprocessor for C and mourn of what was lost making it a language.

Answer 49

C++ is not suited for use in embedded systems

Refer to http://stackoverflow.com/questions/2855884/use-the-right-tool-for-the-job-embedded-programming

Answer 50

C++ programmers are more round-shouldered than other

Answer 51

C++ is basically C with classes.

C++ is much more than that! Is a multi-paradigm language and one that's capable of blending these paradigms harmoniously together to create code that would have been otherwise inferior had we used a single paradigm for the same problem. Skipping more subtle differences (ex: greater type safety, better variable scoping), let's consider just the multi-paradigm aspect.

Let's assume that we're writing a linked list and pretend that no linked list implementation, algorithms, or utilities of any sort to aid us already existed in the standard C++ library or boost.

We decide to use object-oriented techniques and generics and successfully create a list class capable of doing anything one would ever want to do to a linked list: insert elements to it, remove elements from it, and iterate through it.

Now we find that we want to be able to find elements in the list. What do we do?

Given primarily object-oriented techniques at our disposal (only classes), we might be tempted to:

1. simply add a search function directly to the list class. Yet what happens when we later discover that we also want to reverse the list and do all kinds of things with it? The result will be a monolithic class which goes through endless maintenance and revisions. Moreover, if the list implementation details change, this monolithic list might require a complete rewrite!
2. inherit from the list to make super list classes with more functions. This is possibly even worse than #1 as it is prone to slicing issues, incorrect downcasting, and so on. It is also just as vulnerable potentially to breaking on rewrites.
3. Use composition: write a wrapper class which stores the list as a member and provides additional functions to the list. This is far superior to #1 and #2, but requires an interface which duplicates the existing list's functionality. Most people would not choose this approach out of the tedium involved with it.
4. Do the same at #3 but store a reference/pointer to the list and add the additional functions on top along with an accessor to the original list. This is also far superior to #1 and #2, but requires a lengthier syntax on the client to access the original list's interface.
5. write a separate class which provides algorithms to act on lists being passed in. This is the best approach given what we have, but it is primarily a procedural approach regardless of whether we choose to put these functions in a separate class. Unfortunately, most people working in languages that are more strictly object-oriented like Java do not apply this solution enough, instead favoring solutions like #1 and #2. Probably the creation of a new class just to hold new functions is counter-intuitive to most people.

In C++, a multi-paradigm language, the best solution is very obvious. Simply write a separate, free function for such auxiliary functions! When we do this, we get all the benefits of #5: no tight-coupling and therefore no vulnerabilities to list rewrites. The implementation could even change from a singly-linked list to a doubly-linked list or even a completely different sequence type, it doesn't matter as long as the public interface doesn't change. Unlike #3/#4 (composition approach), we don't have to duplicate the public interface of the list.

Finally, when we do things this way, we realize with additional paradigms like generic functional programming, that we can even generalize these separate list algorithms to work on a lot more than list types and even accommodate predicate-based searches without any abstraction cost.

Exception-handling is slower than error-handling (even for non-exceptional cases).

This may be the case on certain compiler implementations, but we need fair comparisons! How many times have we seen a real world system of any scale that properly checks for all possible errors (every possible malloc failure, just for one example) that the program can ever encounter and properly propagates them down the call stack manually to the error-handling site? Almost every function in the system would need to do some error handling to do this as thoroughly as exceptions, and we never find this kind of thoroughness in real world projects of any large scale. Of course any ideally-written code to thoroughly deal with all possible errors is going to be slower than code which ignores a lot of errors and doesn't thoroughly handle them.

Exception-handling is optional with C++ and can simply be turned off without side effects.

Consider what happens with std::list<T, Alloc>::push_back when called to insert an object of type Foo. We invoke the copy ctor of Foo when we do this, and it could throw (ex: call to operator new threw std::bad_alloc). Good implementations of the standard library will deal with this case very gracefully, rolling back everything done so far in the push_back as though it were a transaction, yielding a valid list state as though we never inserted anything to the list. Turn off exception-handling and suddenly we have no way to get this kind of robust behavior. It's the same not just for the C++ standard library, but for all kinds of other C++ libraries that use, as an example, operator new (and not the nothrow version) like boost.

C++ hides code more than C.

Short of exception-handling and implicit constructors (which should generally be avoided), this is often not the case. This is a common argument made by people who lack experience using C++. Given a section of code, a novice might have a difficult time telling you where a destructor will be called given non-exceptional execution flow. An experienced C++ programmer would have no problem pointing this out.

C programmers are used to the idea that operators are not functions. C++ programmers are used to this and can easily point out where an operator will be invoking user-defined functionality. One only need look at whether the operands involved are PODs or not.

To the contrary, a lot of C systems hide code a lot more effectively from the programmer than C++. Consider the C preprocessor, for instance. Nothing hides code better than macros, as we cannot even practically trace through the code in a macro with a debugger.

Using directives should be avoided (ex: using namespace std;)

Sutter argues that using directives are what makes namespaces practical, and for good reasons. Without using directives, we have code that's very vulnerable to ADL-related problems. Virtually everyone agrees that argument-dependent lookup is very evil with the way it's inconsistently implemented across compilers, and using directives mitigate that problem far more effectively than, say, using declarations (ex: using std::cout but forgetting to write using std::operator<< or using std::list but forgetting using std::swap).

Inlining one-liners like accessor functions will make them faster.

Wrong and not even close. For all practical purposes, inlining such functions can reduce code bloat (provided the single line requires less instructions than pushing arguments to the stack, calling the function, popping, and returning), but even then inlining all instances of such code can slow things down as it can cause the compiler to try to equally optimize less commonly-executed code branches with ones that are commonly executed (the compiler can't read your mind about the desired runtime behavior of your code). Inlining should always be done only with the aid of a profiler where one can appropriately analyze the most commonly executed branches of code and selectively inline to help the compiler, even for one-liner functions.

Answer 52

Myth: C++ is high-level and lets you avoid C features.

The inclusion of most of the STL in the C++ standard library did add some much needed high-level data types. But they aren't integrated into the language itself: The core C++ language is still very C-like.

"abc" is a const char[], not a std::string. You can write int x[] = {1, 2, 3}; but not vector<int> x = {1, 2, 3}; (until C++0x becomes popular). this and argv are pointers.

The C++ standard library isn't consistent about using the modern style. fstream takes a const char* for the filename, not a std::string.

Thus, you can't understand C++ without understanding C-style arrays and pointers.

Answer 53

C++ is not a modern language. It is superseded by Java and C#. This one is totally wrong and makes me laugh every time I hear it. Many of my IT friends believe it. Actually, C++ provides more abstraction mechanisms than Java or C#. There is a spin off to this myth.

Newer versions of Visual Studio don't support C++. I heard it from IT folks as well. Some of them believe that Microsoft stopped upgrading its C++ compiler sometime after the introduction of C#.

It is very hard to write exception safe code in C++ compared to Java because of memory leaks. Wrong again. Memory leaks are only a small part of exception safety. There is more to exception safety than memory leaks. Garbage collection helps with memory leaks only.

It is hard to write multithreaded code in C++ compared to Java and C# Wrong. Multithreading is hard in Java and C# as well. Multithreading is a complex and completely different programming paradigm. Once you mastered the art of parallelization, you can use C++, Java or C# to do multithreading.

Java isn't slower than C++ This isn't true. Face it, C++ allows to do more low optimizations, because it is a native language. Competent hackers can cook up highly optimized C++ code which can't be matched in Java no matter how hard you try. But it is true, that incompetent C++ programmers can screw things up easily.

Answer 54

Const accessors are faster

It depends, but usually no

Answer 55

Myth: C++ should be the first programming language a student learns.

Answer 56

i++ is always as fast as ++i

Answer 57

• delete 0 will crash the program (not true)
• pure virtual methods cannot have an implementation (not true)
• C++ code is fast because it's C++ (there's more to the story than that)
• C++ code is usually full of leaks (easily prevented with scope bound resource management)
• C++ is dying (this thread proves that it's not)

Edit
Append '(not true)' to these statements (just in case).

Answer 58

iostream is a lot slower than stdio.h

Reason why iostream performs poorly compared to stdio is because it synchronizes its buffers with stdio ones (in order to ensure that output to the screen from both libraries follows the order of calls in the code). A simple call solves the problem by disabling synchronization:

ios_base::sync_with_stdio(false)

Answer 59

C/C++ is faster than Java in all scenarios