This guide is so primitive that it cannot be called useful. It can possibly be harmful, though, to those who don't know the language well and use this guide as a sole source of information.
C++ Language Quick Guide
21–28 of 28 posts
Re: C++ Language Quick Guide
#22> C++ is a superset of C, and that virtually any legal C program is a legal C++ program. This is not true. One example, void* pointers are not automatically converted to "narrower" types in C++ as they are in C.
Syntactically, C++ is a superset of C though, right? I can't think of any C syntax that's not valid C++, but I'm not exactly am expert in either
C supports variable-length stack-allocated arrays, while C++ doesn't. So code like
void f() {
int x;
scanf("%d", &x); // read from user
int numbers[x]; // dynamic
}
Also, the C "restrict" keyword doesn't exist in C++ either. Add in C's looser typing rules regarding conversions, and C and C++ are basically sibling languages at this point. Their common ancestor language being K&R-era C.
Re: C++ Language Quick Guide
#23Earlier quoted context omitted.
Syntactically, C++ is a superset of C though, right? I can't think of any C syntax that's not valid C++, but I'm not exactly am expert in either
C supports variable-length stack-allocated arrays, while C++ doesn't. So code like void f() { int x; scanf("%d", &x); // read from user int numbers[x]; // dynamic } is legal C, but not C++. Also, the C "restrict" keyword doesn't exist in C++ either. Add in C's looser typing rules regarding conversions, and C and C++ are basically sibling languages at this point. Their common ancestor language being K&R-era C.
> C supports variable-length stack-allocated arrays, while C++ doesn't. So > code like
>
> void f() {
> int x;
> scanf("%d", &x); // read from user
> int numbers[x]; // dynamic
> }
I just pasted this in a file (and added `#include `) and compiled with g++, and it gave no errors or warnings and produced a *.o file, so maybe it does work?
Re: C++ Language Quick Guide
#24Earlier quoted context omitted.
Syntactically, C++ is a superset of C though, right? I can't think of any C syntax that's not valid C++, but I'm not exactly am expert in either
> I can't think of any C syntax that's not valid C++, enum toto { a = 1 }; enum toto b = 1; Fixing versions of both standards could bring in more examples (like trailing comma in enums and use of the names reserved in C++, by the C code). Overall, ironically, as typing is stronger in C++ (which I agree is a non-syntactic change), poor C code (using lots of unjustified casts), will require less modifications to be com…
Thanks for the example!
Re: C++ Language Quick Guide
#25Earlier quoted context omitted.
C supports variable-length stack-allocated arrays, while C++ doesn't. So code like void f() { int x; scanf("%d", &x); // read from user int numbers[x]; // dynamic } is legal C, but not C++. Also, the C "restrict" keyword doesn't exist in C++ either. Add in C's looser typing rules regarding conversions, and C and C++ are basically sibling languages at this point. Their common ancestor language being K&R-era C.
> C supports variable-length stack-allocated arrays, while C++ doesn't. So > code like > > void f() { > int x; > scanf("%d", &x); // read from user > int numbers[x]; // dynamic > } I just pasted this in a file (and added `#include `) and compiled with g++, and it gave no errors or warnings and produced a *.o file, so maybe it does work?
That's because gcc supports it as an extension to C++. It's not an official part of the language, and using it in C++ code is therefore not portable across compilers/platforms.
Re: C++ Language Quick Guide
#26Earlier quoted context omitted.
> C supports variable-length stack-allocated arrays, while C++ doesn't. So > code like > > void f() { > int x; > scanf("%d", &x); // read from user > int numbers[x]; // dynamic > } I just pasted this in a file (and added `#include `) and compiled with g++, and it gave no errors or warnings and produced a *.o file, so maybe it does work?
That's because gcc supports it as an extension to C++. It's not an official part of the language, and using it in C++ code is therefore not portable across compilers/platforms.
clang++ seems to work as well. I don't have a Windows machine handy to try MSVC, though
Re: C++ Language Quick Guide
#27Does this guide have anything about references? Didn't find anything about that, but maybe I missed it, I think its a pretty important topic to cover. Also didn't see anything about the different types of constructors.