error: unknown type name ‘namespace’

[jiapei100]

Hi,

My OS: Ubuntu 16.04.4
GCC/G++: Ubuntu 5.4.0-6ubuntu1~16.04.9
OpenCV: manually installed 3.4.1
I'm actually building VLC with OpenCV.
And, I came across the following ERROR message:

/usr/local/include/opencv2/core/cvdef.h:485:1: error: unknown type name ‘namespace’
 namespace cv {
 ^
/usr/local/include/opencv2/core/cvdef.h:485:14: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘{’ token
 namespace cv {
              ^

And in /usr/local/include/opencv2/core/cvdef.h, the code snippet is:

// Integer types portatibility
#ifdef OPENCV_STDINT_HEADER
#include OPENCV_STDINT_HEADER
#else
#if defined(_MSC_VER) && _MSC_VER < 1600 /* MSVS 2010 */
namespace cv {
typedef signed char int8_t;
typedef unsigned char uint8_t;
typedef signed short int16_t;
typedef unsigned short uint16_t;
typedef signed int int32_t;
typedef unsigned int uint32_t;
typedef signed __int64 int64_t;
typedef unsigned __int64 uint64_t;
}
#elif defined(_MSC_VER) || __cplusplus >= 201103L
#include <cstdint>
namespace cv {
using std::int8_t;
using std::uint8_t;
using std::int16_t;
using std::uint16_t;
using std::int32_t;
using std::uint32_t;
using std::int64_t;
using std::uint64_t;
}
#else
#include <stdint.h>
namespace cv {
typedef ::int8_t int8_t;
typedef ::uint8_t uint8_t;
typedef ::int16_t int16_t;
typedef ::uint16_t uint16_t;
typedef ::int32_t int32_t;
typedef ::uint32_t uint32_t;
typedef ::int64_t int64_t;
typedef ::uint64_t uint64_t;
}
#endif
#endif

It looks if the build goes to #include <stdint.h>,
VLC's compiler is using gcc instead of g++?
And I wonder why __cplusplus >= 201103L ?
Here is my case:

$ gcc --version
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

In such a case, how do you comapre 201103L and ** (Ubuntu 5.4.0-6ubuntu1~16.04.9) 5.4.0 20160609**?

Cheers
Pei

[jiapei100]

@alalek
Hi, alalek, at least please let me know where is the duplicate issue? from where I can find the answer, or at least a similar question has been asked?

I met this problem again just now while I'm building another package, which is also based on OpenCV. What is the issue# that my issue is duplicate with ?

[tomoaki0705]

such as #10963?
@jiapei100 , I suggest to search before you claim