How to judge whether a project is a c or c++ project?

Question

wprintf(L"Selecting Audio Input Device: %s\n", 
                            varName.bstrVal);
if(0 == wcscmp(varName.bstrVal, L"IP Camera [JPEG/MJPEG]"))
{
    ...
}

hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,
                        IID_IBaseFilter, (void **)&pGrabberF);

The above is from a .cpp file ,but as you see its content is quite c-style.

Will you call it a c or c++ project?

Anyone can take a C-like snippet from a C++ file. It's impossible to determine based on these few lines. Are there any classes being delcared or used? Are templates being used? Any C++ specific libraries being used? Answering those questions will help you more. — FrustratedWithFormsDesigner, Sep 13 '10 at 13:47
No class and template used.For the 3rd question,pls define C++ specific libraries... — COMer, Sep 13 '10 at 13:59
I don't see a coherent question here. What does it matter what I call it? — David Thornley, Sep 13 '10 at 14:19

score 4 · Accepted Answer · edited May 23 '17 at 11:47

4

It simply depends how you compile it.

Some code will compile as both, it's considered C++ code if it gets compiled by a C++ compiler.

C is NOT an exact subset of C++ by the way.

Often you can deduce with a fast glance simply by the file's extension, although it's possible to put C code in a .cc extension or .cpp extension and you can also put C++ code in a .c extension, but that would be pretty rare.

edited May 23 '17 at 11:47

Community

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answered Sep 13 '10 at 13:44

Brian R. Bondy

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It seems to me visual studio uses the same compiler for c and c++,doesn't it? – COMer Sep 13 '10 at 13:57
@COMer: For the most part. If you use .c though it will compile as C, and will allow things like implicit casts from `void*`. – Billy ONeal Sep 13 '10 at 13:59
I added one extra line in my post,what about now? – COMer Sep 13 '10 at 14:07
@COMer: Yes you can still call it a C++ project. The Win32 APIs are built to work with C and you can also use C++. – Brian R. Bondy Sep 13 '10 at 14:11
Do you mean all Win32 APIs can be used in both c and c++? – COMer Sep 13 '10 at 14:39
VC++ is hardly a C compiler. It's awful. However I do believe that C++03 "merged" in C89, and this is what VC++ supports. It's a real shame that your first experience with C is through Windows and MSVC. – Matt Joiner Sep 14 '10 at 02:47

score 1 · Answer 2 · answered Sep 13 '10 at 13:47

1

I'd call it a C project because I wouldn't be caught dead using C-style string comparison via raw pointer in C++. Exceptions or other stuff would annihilate that code. A correct solution would be to change bstrVal into a BSTR class, which has an operator== overload for wchar_t*.

answered Sep 13 '10 at 13:47

Puppy

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BSTR is not a class, it's a type (OLECHAR*). Did you mean _bstr_t or CComBSTR? – Steve Townsend Sep 13 '10 at 13:48
That's why I suggested CHANGE it into an RAII self-releasing operator-overloaded class. – Puppy Sep 13 '10 at 13:53

Matt Joiner · Answer 3 · 2010-12-13T01:11:29.413

0

I'd say it depends on linkage. If it's a library intended to be C linkable, it's C. If it requires C++ to link with, it's C++. If it provides both options, it's both.

If however it's not a library, and it requires a C++ compiler to build, it's a C++ project.

Update0

It's still a matter of linkage. The code you've given will compile under both C and C++.

edited Dec 13 '10 at 01:11

answered Sep 13 '10 at 13:46

Matt Joiner

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I added one extra line in my post,what about now? – COMer Sep 13 '10 at 14:10

How to judge whether a project is a c or c++ project?

3 Answers3

Update0