For as long as I can remember, I have heard people say C/C++ when referring to
a project written in C and or C++. A lot of programming/developer jobs also
refer to C/C++ when they need a programmer who knows either C or C++. To most
people who have never touched C or C++ this might not seem like a big deal.
However, the problem is that when people say this term (C/C++) they make it
seem like C and C++ are similar or closely related programming languages.
That is not true. Although C++ was based off of C when it was first
created, these two languages have slowly drifted apart over the years to the
point where they share less and less in common.
C and C++ are VERY Different
There is probably someone who is going to say, “Well you can write C code in
a C++ program, so technically C is a subset of C++.” The only problem is that
you can write C code in Rust,
Go, Kotlin,
and basically almost every other language out there! So should I refer to Rust,
Go, and Kotlin as C/Rust, C/Go, and C/Kotlin? Obviously no.
C with Classes
“But C++ is just C with classes!”
No, it isn’t. Anyone who says this obviously has never worked with C++. C++ has
completely different standard libraries, implementations, and standards than C.
It is true that when C++ was first made it was just C with classes, that has
long been false ever since C++ has implemented features separate from C.
Incompatibility
Void Pointers
One such case where C++ is incompatible with C is with void pointers.
For example, this program will compile with a C compiler (like GCC), but it
will not compile with a C++ compiler (like G++):
#include All this code does is allocate 5 bytes to an integer pointer a. This program
works perfectly fine when compiled with GCC, but if I compile this program with
G++ this error is returned:
main.c: In function 'int main()':
main.c:4:24: error: invalid conversion from 'void*' to 'int*' [-fpermissive]
4 | int *a = malloc(5);
| ~~~~~~^~~
| |
| void*
The reason this happens is that malloc returns a void pointer and C++ cannot
convert a void pointer into an integer pointer unless it is specifically cast
to an integer pointer.
K&R Syntax
Another big incompatibility with C and C++ is that C++ is actually incompatible
with K&R syntax. Given this example function formatted in K&R syntax:
int gcd(a, b)
int a;
int b;
{
if (b == 0)
return a;
return gcd(b, (a % b));
}
It will compile perfectly fine for GCC (as expected), however G++ gives us
another set of errors…
gcd.c:3:9: error: 'a' was not declared in this scope
3 | int gcd(a, b)
| ^
gcd.c:3:12: error: 'b' was not declared in this scope
3 | int gcd(a, b)
| ^
gcd.c:3:13: error: expression list treated as compound expression in initializer [-fpermissive]
3 | int gcd(a, b)
| ^
gcd.c:6:1: error: expected unqualified-id before '{' token
6 | {
| ^
This makes it almost impossible to use K&R syntax with C++ unless you format
your function arguments according to ASCI C.
There are also many other things in C that will not transfer over to C++, but
I think you already get the picture by now. These incompatibilities are not
anything that would break the entire C language if used in conjunction with
C++, but these small differences slowly add up.
Hard for Beginners
Not differentiating between C and C++ also has the side effect of ostracizing new
users. Many beginner programmers are lead by the term “C/C++” to think that
they’re basically the same language. In fact there are many tutorials out there
that are advertised as “C/C++ tutorials”, continuing the confusion.
This can also scare away C beginners by making them think that understanding
the complexities of C++ are required to understand C (SPOILER: They’re not).
I have fallen for this trap in the past, as well as many others.
C is honestly a very simple programming language, C++ is not.
C and C++ Programmers are VERY Different
With the new C++ standards given throughout the years like C++11, C++20, and
etc. C++ programmers have been given more tools and functions that don’t exist
in standard C. This usually results in modern C programs having more lines of
code than modern C++, however this means that modern C is usually more readable
than modern C++. Here is an example question from LeetCode.
Solutions differ, but most C solutions look something like this:
int maximumCount(int *nums, int numsSize) {
int pos = 0, neg = 0;
for (int i = 0; i < numsSize; i++) {
if (nums[i] > 0) pos++;
else if (nums[i] < 0) neg ++;
}
return pos > neg ? pos : neg;
}
Even though this code is pretty compact for C standards it is still very
readable. Now for the C++ solutions, there are a lot of variations to this
solution so I will use one that’s different enough from C.
int maximumCount(std::vector<int> nums) {
auto [a, b] = std::equal_range(nums.begin(), nums.end(), 0);
return std::max(std::distance(nums.begin(), a), std::distance(b, nums.end()));
}
This uses vector and algorithm from the C++ standard library.
As you can see this code is much more compact but is definitely not as
readable as the C code. Although the C solution can be compiled by a C++
compiler I wanted to highlight just how different they can be from each other.
This is but one example of how C and C++ programmers have slowly separated
when it comes to programming.
Many C Programmers Won’t Touch C++
I’m pretty sure everyone knows the C programmer stereotype by now, the only
thing is that it is TRUE.
Lots of Suckless users and developers only use
C and POSIX shell in their programs. Cat-v endorses
C and C-like languages, but despises C++. Even
Linus Torvalds,
the creator Linux and Git, won’t touch C++.
Heck, even I love C but I can’t stand programming in C++.
This is probably the biggest reason why employers SHOULD NOT put C/C++
on job descriptions, especially if they’re only looking for C developers.
All they are doing is scaring away competent C developers.
The Solution
If you’re referring to a C program or programmer just say “C”.
If you’re referring to a C++ program or programmer just say “C++”.
If you’re referring to both used separately say something like:
- C and C++
- C, C++
- C++ with C
- Etc.
NOT C/C++
Only if you’re using C together with C++ would it be acceptable to
say C/C++.
