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Stop Saying C/C++

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 common1.

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 Zig, Go, Nim, and basically almost every other language out there has a C FFI! So should I refer to Zig, Go, and Nim as C/Zig, C/Go, and C/Nim? 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 classes2, 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 <stdlib.h>

int main() {
	int *a = malloc(5);
	return 0;
}

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. (I know not many people care about K&R syntax, but I think that it is still an important difference).

There are also many other things in C that will not transfer over to C++ like complex numbers, default return types, and more, 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 library3. 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

NOT C/C++

Only if you’re using C together with C++ would it be acceptable to say C/C++.

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