4 ms·

Why not just pick and choose what you need from C++? For all the hate that C++ gets, one nice thing is it doesn't force anything down your throat. Between simpl

by btmorex 16y ago

Why not just pick and choose what you need from C++? For all the hate that C++ gets, one nice thing is it doesn't force anything down your throat. Between simple not using features, and compile time options (disabling exceptions for example), you NEVER have to pay for a feature that you don't want or need. He could have literally written C-style code except used C++ just to create a few generic data stores instead of using all of this preprocessor magic which I guarantee is more fragile/harder to debug than basic C++ templates.

jedbrown 16y ago
FWIW, C++ does force some things on you, such as automatically typedefing structs instead of giving you a separate namespace, not warning about multiple declarations with different arguments (because function overloading is a feature), not warning about multiple definitions in different compilation units (linker just picks one, assumes they are equivalent), having to cast assignment of void* to a typed pointer (ugly and redundant), slower compilation, and generally later errors/warnings (thus usually more cryptic and less useful, although it does stricter type checking in some ways, so this point is not completely clear-cut).
- shin_lao 16y ago
  Hi, just want to bounce on the "cast your void to a pointer"*, actually you don't need to do that if you don't use an object oriented paradigm à la Java, but go generic full speed and use return by value. No pointers, little or no casting.
  - jedbrown 16y ago
    > go generic full speed What does this mean? As a simple example, suppose I use malloc to allocate memory (because I don't want to allocate with new which would oblige me to handle exceptions and prevent me from handing ownership over to a C client or using an allocator provided by a C client (without extra work)). I have to cast the return value as in struct Foo *x = (struct Foo*)malloc(n*sizeof(*x)); instead of struct Foo *x = malloc(n*sizeof(*x)); This looks purely cosmetic, but in C, I can write the macro #define MallocA(n,p) (!(*(p) = malloc((n)*sizeof(**(p)))) which then works with a standard error checking convention struct Foo *arr; err = MallocA(n,&arr);CHK(err); This doesn't work in C++ without non-portable typeof or evil and less safe (not conforming for function pointers) *(void**)(p) = malloc((n)*sizeof(**(p))) Similarly, if a client registers a callback with a context, I store their context in a void* and pass it back to them int UserCallback(void *ctx,...) { struct User *user = (struct User*)ctx; instead of int UserCallback(void *ctx,...) { struct User *user = ctx; I understand that this is just cosmetic. I don't see how "going generic full speed" helps with this. Also note that aggregate returns are slower for all but trivially small structures, and downright bad for big structures.

by btmorex 16y ago

jedbrown 16y ago

FWIW, C++ does force some things on you, such as automatically typedefing structs instead of giving you a separate namespace, not warning about multiple declarations with different arguments (because function overloading is a feature), not warning about multiple definitions in different compilation units (linker just picks one, assumes they are equivalent), having to cast assignment of void* to a typed pointer (ugly and redundant), slower compilation, and generally later errors/warnings (thus usually more cryptic and less useful, although it does stricter type checking in some ways, so this point is not completely clear-cut).

shin_lao 16y ago
Hi, just want to bounce on the "cast your void to a pointer"*, actually you don't need to do that if you don't use an object oriented paradigm à la Java, but go generic full speed and use return by value. No pointers, little or no casting.
- jedbrown 16y ago
  > go generic full speed What does this mean? As a simple example, suppose I use malloc to allocate memory (because I don't want to allocate with new which would oblige me to handle exceptions and prevent me from handing ownership over to a C client or using an allocator provided by a C client (without extra work)). I have to cast the return value as in struct Foo *x = (struct Foo*)malloc(n*sizeof(*x)); instead of struct Foo *x = malloc(n*sizeof(*x)); This looks purely cosmetic, but in C, I can write the macro #define MallocA(n,p) (!(*(p) = malloc((n)*sizeof(**(p)))) which then works with a standard error checking convention struct Foo *arr; err = MallocA(n,&arr);CHK(err); This doesn't work in C++ without non-portable typeof or evil and less safe (not conforming for function pointers) *(void**)(p) = malloc((n)*sizeof(**(p))) Similarly, if a client registers a callback with a context, I store their context in a void* and pass it back to them int UserCallback(void *ctx,...) { struct User *user = (struct User*)ctx; instead of int UserCallback(void *ctx,...) { struct User *user = ctx; I understand that this is just cosmetic. I don't see how "going generic full speed" helps with this. Also note that aggregate returns are slower for all but trivially small structures, and downright bad for big structures.