Generic dynamic array in 60 lines of C
gist.github.com
Generic dynamic array in 60 lines of C
1–10 of 110 posts
Re: Generic dynamic array in 60 lines of C
#2data (startptr), endptr & capacity?! Memory might be cheap enough to waste, but more derefs do not help timings.
Re: Generic dynamic array in 60 lines of C
#3data (startptr), endptr & capacity?! Memory might be cheap enough to waste, but more derefs do not help timings.
Capacity may not be equal to size.
Re: Generic dynamic array in 60 lines of C
#4data (startptr), endptr & capacity?! Memory might be cheap enough to waste, but more derefs do not help timings.
Three pointers (or two and a size, or one and two sizes) is pretty standard for dynamic arrays. It lets you allocate more than one element a time when repeatedly appending one element.
No checking malloc or realloc though. The anonymous struct is dubious too, though maybe being unable to pass these things to functions is a feature.
Re: Generic dynamic array in 60 lines of C
#5yes, i know growth by a factor of 2 has issues under certain usage patterns. those are less likely to be problematic when there is more stuff going on than just growing the buffer - you can use the "hole" for other allocations.
Re: Generic dynamic array in 60 lines of C
#6Heavy use of macros to do metaprogramming is a strong sign it's time to move to a more powerful language.
Re: Generic dynamic array in 60 lines of C
#7data (startptr), endptr & capacity?! Memory might be cheap enough to waste, but more derefs do not help timings.
Three pointers (or two and a size, or one and two sizes) is pretty standard for dynamic arrays. It lets you allocate more than one element a time when repeatedly appending one element. No checking malloc or realloc though. The anonymous struct is dubious too, though maybe being unable to pass these things to functions is a feature.
functions can work with just pointer / size / stride. think of it as stl iterators, there's no real point to be passing the container itself around.
however, you can still do that, if you really want.
just `typedef DYN_ARR_OF(widget) widget_array;` and now you have a name-able type, and can even have dynamic-arrays-of-dynamic-arrays (`DYN_ARR_OF(widget_array)`).
Re: Generic dynamic array in 60 lines of C
#8The code has integer overflow even on 64 bit CPU due to using uint32 for capacity.
Re: Generic dynamic array in 60 lines of C
#9Heavy use of macros to do metaprogramming is a strong sign it's time to move to a more powerful language.
Yeah that's a great opinion and all but generally C is used because it HAS to be used these days. No one is going to use this code for building a web application or will be tossing it into legacy code.
Re: Generic dynamic array in 60 lines of C
#10This seems pretty sensical to me except that it achieves its small size by sacrificing error checking and handling, even in the (aiui) non-exceptional case of realloc() returning NULL. This is of course classic C program behaviour so perhaps that's fine ;-)