Comment by jandrewrogers
4 months ago
This is not a convincing argument for C. None of this matches my experience across many companies. In particular, the specific things you cite — excessive dynamic memory usage, exceptions, bloat — are typically only raised by people who don’t actually use C++ in the kinds of serious applications where C++ is the tool of choice. Sure, you could write C++ the way you describe but that is just poor code. You can do that in any language.
For example, exceptions have been explicitly disabled on every C++ code base I’ve ever worked on, whether FAANG or a smaller industrial company. It isn’t compatible with some idiomatic high-performance software architectures so it would be weird to even turn it on. C++ allows you to strip all bloat at compile-time and provides tools to make it easy in a way that C could only dream of, a standard metaprogramming optimization. Excessive dynamic allocation isn’t a thing in real code bases unless you are naive. It is idiomatic for many C++ code bases to never do any dynamic allocation at runtime, never mind “excessive”.
C++ has many weaknesses. You are failing to identify any that a serious C++ practitioner would recognize as valid. In all of this you also failed to make an argument for why anyone should use C. It isn’t like C++ can’t use C code.
This risks becoming a no true Scotsman, but it is indeed true that there is really no common idiomatic C++. Even the same code base can use vastly different styles in different areas.
Even regarding exceptions, I would not touch them anywhere close to the critical path, but, for example, during application setup I have no problem with them. And yet I know of people writing very high performance applications that are happy to throw on the critical path as long as it is a rare occurence.
> Sure, you could write C++ the way you describe but that is just poor code.
C++ puts people into a sea of complexity and then blames them when they do not get a good result. The purpose of high level programming languages is to make things easier for people, not make them even more likely to fail to write good code and then blame them when they do not.
> For example, exceptions have been explicitly disabled on every C++ code base I’ve ever worked on, whether FAANG or a smaller industrial company.
Unfortunately, C++ does not make exceptions optional and even if you use a compiler flag to disable them, libraries can still throw them. Just allocating memory can throw them unless you use the nothrow version of the new operator that C++11 introduced. Alternatively, you could use malloc with a placement new and then manually call the destructor before freeing the memory. As far as I know, many C++ developers who disable exceptions do not do either. Then when a memory allocation fails, their program terminates.
That said, there are widely used C++ code bases that rely on exception handling. One of the most famous is the Windows NTFS driver, which reportedly makes heavy use of structured exception handling:
https://blog.zorinaq.com/i-contribute-to-the-windows-kernel-...
> It isn’t compatible with some idiomatic high-performance software architectures so it would be weird to even turn it on. C++ allows you to strip all bloat at compile-time and provides tools to make it easy in a way that C could only dream of, a standard metaprogramming optimization. Excessive dynamic allocation isn’t a thing in real code bases unless you are naive. It is idiomatic for many C++ code bases to never do any dynamic allocation at runtime, never mind “excessive”.
I have seen plenty of C++ software throw exceptions in wine, since it prints information about it to the console. It is amazing how often exceptions are used in the normal operation of such software. Contrary to your assertions of everyone turning off exceptions, these exceptions are caught and handled. Of course, this goes unseen on the original platform, so the developers likely have no idea about all of the exceptions that their code throws.
As for excessive dynamic memory allocations, C++11 introduced move semantics to eliminate a major source of them, and that very much was a problem in real code. It still can be, since you need to always use std::move and define move constructors. C++ itself tends to discourage use of intrusive data structures (as they break encapsulation), which means doing more dynamic allocations than C code does since heavy use of intrusive data structures in C code avoids allocations that are mandatory without them.
> C++ has many weaknesses. You are failing to identify any that a serious C++ practitioner would recognize as valid. In all of this you also failed to make an argument for why anyone should use C.
My goal had been to say that performance was not a reason to use C++ over C, since C++ is often slower. Had my goal been different, there is plenty of material I could have used. For example, I could have noted the binary compatibility breakage that occurred for C++11 in GCC 5.0, the horrendous error messages from types that are effectively paragraphs, changes in the STL definitions across different versions that break code, and many other things, but I was not trying to throw stones at an obviously glass house.
> It isn’t like C++ can’t use C code.
It increasingly cannot. If C headers use variably modified types and do not have a guard macro an alternative for C++ that turns them into regular pointers, C++ cannot use the header. Here is an example of code using it that a C++ compiler cannot compile:
https://godbolt.org/z/T5T4Y1n68
The C preprocessor also now has generics which are not supported by C++ either:
https://godbolt.org/z/cof14W7vM