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error: unknown type name ‘namespace’

Posted: 08 Mar 2018 06:54
by 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:

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/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:

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// 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:

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$ 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

Re: error: unknown type name ‘namespace’

Posted: 12 Mar 2018 11:20
by chubinou
OpenCV C bindings are broken in OpenCV 3 and they have no intention to fix it [1]. at the moment, VLC only compiles with opencv 2

[1] https://github.com/opencv/opencv/issues/8658