# Compilation issues with gnu cc 11.2.0 (not C++)

**URL:** <https://forum.opencv.org/t/compilation-issues-with-gnu-cc-11-2-0-not-c/8248>\
**Category:** Uncategorized\
**Tags:** build, historical\
**Created:** [April 3, 2022, 5:37pm UTC](https://forum.opencv.org/t/compilation-issues-with-gnu-cc-11-2-0-not-c/8248 "2022-04-03T17:37:54Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![khimaros](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/khimaros/32/4918_2.png) [@khimaros](https://forum.opencv.org/u/khimaros)\
**Post date:** [April 3, 2022, 5:37pm UTC](https://forum.opencv.org/t/compilation-issues-with-gnu-cc-11-2-0-not-c/8248/1 "2022-04-03T17:37:54Z")

</div>

##### System information (version)

- OpenCV =\> 4.5.4
- Operating System / Platform =\> Debian Bookworm
- Compiler =\> GNU 11.2.0

##### Detailed description

i’m attempting to modernize and build [GitHub - fpeder/XKin: eXtanble hand pose and gesture recognition library for Kinect](https://github.com/fpeder/XKin)

while doing this, i encountered an issue with opencv’s build system.

`core/core_c.h` includes `core/type_c.h` which in turn includes `core/cvdef.h`

there is a block of definitions which assume C++11.

when i `#ifdef __cplusplus` this section, the build progresses further.

the issue is present in master branch and can be seen in this block: [opencv/modules/core/include/opencv2/core/cvdef.h at 4.x · opencv/opencv · GitHub](https://github.com/opencv/opencv/blob/4.x/modules/core/include/opencv2/core/cvdef.h#L762)

was support for cc dropped by opencv intentionally?

##### Steps to reproduce

install opencv (from apt) and compile libfreenect with the opencv wrapper.

then attempt to build XKin:

```auto
$ git clone https://github.com/fpeder/XKin
$ mkdir build && cd build && cmake .. && make

```

---

<div class="post-metadata">

**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [April 3, 2022, 7:41pm UTC](https://forum.opencv.org/t/compilation-issues-with-gnu-cc-11-2-0-not-c/8248/2 "2022-04-03T19:41:45Z")

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yes. no more C API.

that’s been **deprecated** since release of v2, everyone who still used it in v3 got yelled at, and the C API was **removed** in v4