Adding C++ support to C thought library?

[sept]

Is there an library for C compiler which will add C++'s features?

[matsp]

Not really, since C++ is a different language. Some compilers (and the C99 standard) has cherry picked a few things that they find handy out of the C++ language (variable sized arrays and "variable declarations anywhere" being the most obvious ones).

On the one hand, you could say that all C++ features can actualy be achieved in C. On the other hand, C++ _IS_ a different language, and to add those features to C would require changing the compiler - you can't just use a library as replacement.

But bear in mind that the first C++ compiler actually produced C code, and used a standard C compiler to generate machine code.

--
Mats

[Elysia]

Is there a reason you can't use C++ instead?

[Shiro]

I don't know of such a library, but if you need to implement an object orientated design in C, then there are different strategies for this. Some links that might be useful:

ldeniau.web.cern.ch/ldeniau/html/oopc/oopc.html
www.planetpdf.com/codecuts/pdfs/ooc.pdf
www.bolthole.com/OO-C-programming.html

[herWter]

>>Not really, since C++ is a different language. Some compilers (and the C99 standard) has cherry picked a few things that they find handy out of the C++ language (variable sized arrays and "variable declarations anywhere" being the most obvious ones).

When did C++ get variable sized arrays?

[matsp]

>>Not really, since C++ is a different language. Some compilers (and the C99 standard) has cherry picked a few things that they find handy out of the C++ language (variable sized arrays and "variable declarations anywhere" being the most obvious ones).

When did C++ get variable sized arrays?

I actually meant "non-compile-time size arrays", such as:

int func(const int n)
{
    int arr[n];
    ... 
}

int main()
{
   int n;
   cout << "Enter number of elements:";
   cin >> n;

   int x = func(n);
   ...

--
Mats

[zacs7]

You can do that in C99, so it's not really a C++ feature

[matsp]

You can do that in C99, so it's not really a C++ feature

Yes, but that's what I said:

Some compilers (and the C99 standard) has cherry picked a few things that they find handy out of the C++ language (variable sized arrays and "variable declarations anywhere" being the most obvious ones).

--
Mats

[Elysia]

But since when did C++ allow arrays with a non-compile time constant arrays?
Your example doesn't compile, mats!

[zacs7]

Ooops my bad . Sorry matsp.

[matsp]

Sorry, C++ doesn't technically support that, but gcc does as an extension - I got myself confused [again]. I'm not sure if C99 does support it or not - gcc -std=c99 -pedantic does compile this:

#include <stdio.h>

double func(const int n)
{
    int arr[n];
    double d = 0;
    for(int i = 0; i < n; i++)
    {
	arr[i] = 1 << i;
    }
    for(int j = 0; j < n; j++)
    {
	d += 1.0 / arr[j];
    }
    return d;
}

int main()
{
   int n;
   printf("Enter number of elements:");
   scanf("%d", &n);

   printf("Result=%f\n", func(n));
   return 0;
}

whilst g++ -std=c++98 -pedantic does not. Remove pedantic and it does.

--
Mats

[CornedBee]

VLAs were a GCC extension and were adopted in C99. They're not part of any C++ standard, and won't be part of C++0x, AFAIK.
GCC's documentation says, however, that their implementation of VLAs is not 100% compliant with the C99 definition.
http://gcc.gnu.org/c99status.html

A good library for getting object-oriented functionality into C is glib/gobject.

[sept]

Is there a reason you can't use C++ instead?

Yes, that's the whole point asking here.

A library I am using compiles only with a C compiler, but not with a C++ compiler. My platform and compiler is outdated. Also no C++ compiler available with full (compared to recently compilers) standard support.

C++ as "addon" for a standard C compiler would have been a nice thing, but if it doesn't exists I am out of luck.

[CornedBee]

That would be quite impossible. Different syntax means the compiler itself must change.

[Shiro]

I'm not sure if I understand your problem well, but you can mix C and C++ code. In short you compile your C code with the C compiler and C++ code with the C++ compiler. By supplying linkage specifications you're able to use C code within C++ code.