arm-none-eabi-g++ doesn't know keyword restrict

[Miro Petrak]

Env:

• gcc version 10.3.1 20210824 (release) (GNU Arm Embedded Toolchain 10.3-2021.10)
• std=c++11
• nRF Connect SDK v2.0.0

Including nrf_socket.h from nrfxlib/nrf_modem/include/ in C++ project causes error because C++ doesn't know keyword restrict.

nrf_socket.h:626:49: error: expected ',' or '...' before 'buffer'
  626 | ssize_t nrf_recvfrom(int socket, void *restrict buffer, size_t length, int flags,
      |                                                 ^~~~~~

Replacing restrict with __restrict solved this problem.

C++ does not have standard support for restrict, but many compilers have equivalents that usually work in both C++ and C, such as the GCC's and Clang's __restrict__...

In Unix-style compilers such as GCC and Clang, __restrict and __restrict__ mean exactly the same as their C counterpart

Restrict

[ovrebekk]

Hi Miro

Thanks for the report. I will get one of the developers to have a look at this, and get back to you later. 

Best regards
Torbjørn