Giving C a superpower: custom header file (safe_c.h)

Post by TuxSH » Mon, Nov 17, 2025, 6:42 PM UTC

accelbred wrote: post #126

woodruffw wrote: post #36

Intentionally or not, this post demonstrates one of the things that makes safer abstractions in C less desirable: the shared pointer implementation uses a POSIX mutex, which means it’s (1) not cross platform, and (2) pays the mutex overhead even in provably single-threaded contexts. In other words, it’s not a zero-cost abstraction. C++’s shared pointer has the same problem; Rust avoids it by having two types (Rc and…

Unfortunately, for C++, thats not true. At least with glibc and libstdc++, if you do not link with pthreads, then shared pointers are not thread-safe. At runtime it will do a symbol lookup for a pthreads symbol, and based off the result, the shared pointer code will either take the atomic or non-atomic path. I'd much rather it didnt try to be zero-cost and it always used atomics...

Post by lelanthran » Mon, Nov 17, 2025, 6:45 PM UTC

KerrAvon wrote: post #107

hypeatei wrote: post #57

Earlier quoted context omitted.

I think these threads attract people that write code for performance-critical use cases which explains the "cosmic horror" over pretty benign things. I agree though: most programs aren't going to be brought to their knees over some GC sweeps every so often.

Outside of hobbyist things, performance-critical code is the only responsible use case for a non-memory safe language like C in 2025, so of course it does. (Even that window is rapidly closing, though; languages like Rust and Swift can be better than C for perf-critical things because of the immutability guarantees.)

Post by jvanderbot » Mon, Nov 17, 2025, 6:52 PM UTC

Snarwin wrote: post #72

Phil_Latio wrote: post #63

Earlier quoted context omitted.

> Because about 99% of the time the garbage collect is a negligible portion of your runtime In a system programming language?

There's plenty of application-level C and C++ code out there that isn't performance-critical, and would benefit from the safety a garbage collector provides.

Post by sramsay » Mon, Nov 17, 2025, 7:01 PM UTC

KerrAvon wrote: post #107

hypeatei wrote: post #57

Earlier quoted context omitted.

I think these threads attract people that write code for performance-critical use cases which explains the "cosmic horror" over pretty benign things. I agree though: most programs aren't going to be brought to their knees over some GC sweeps every so often.

Outside of hobbyist things, performance-critical code is the only responsible use case for a non-memory safe language like C in 2025, so of course it does. (Even that window is rapidly closing, though; languages like Rust and Swift can be better than C for perf-critical things because of the immutability guarantees.)

Post by bangaladore » Mon, Nov 17, 2025, 7:08 PM UTC

sesm wrote: post #78

krapht wrote: post #2

C++: "look at what others must do to mimic a fraction of my power" This is cute, but also I'm baffled as to why you would want to use macros to emulate c++. Nothing is stopping you from writing c-like c++ if that's what you like style wise.

Embedded CPU vendors not shipping C++ compilers is what usually stops people.