How to solve this [All] Error 2 in this case? - c++

Question

So I coding a simple tensor with Eigen as follows:
#define _USE_MATH_DEFINES
#include <iostream>
#include <cmath>
#include <Eigen/Dense>
#include <unsupported/Eigen/CXX11/Tensor>
using namespace Eigen;
using namespace std;
int main () {
Tensor<double, 3> A(4,5,6); // 3 dimensions (4x5x6)
A.setZero();
A(0,1,2) = 1.7;
A(1,2,2) = -1.5;
cout<<A(1,2,2)<<endl;
return 0;
}
But then I get the following error and I looked around the internet for help, but sadly I am still clueless. I always get this error with my more advanced code, so I decided to do a small code just to test when I get this error. Note: I didn't get this error when I was did the same with an Eigen matrix. Only when I changed to a tensor, did I get this error. Then afterwards I changed it back to a matrix and I somehow get the same error now? However, even in my more advanced code I don't even have any tensors, but for some reason still get this error. Can someone please help me as this is driving me insane?
C:\WINDOWS\system32\cmd.exe /C C:/MinGW/bin/mingw32-make.exe -j4 SHELL=cmd.exe -e -f Makefile
"----------Building project:[ Test - Debug ]----------"
mingw32-make.exe[1]: Entering directory 'C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test'
mingw32-make.exe[1]: Leaving directory 'C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test'
mingw32-make.exe[1]: Entering directory 'C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test'
C:/MinGW/bin/g++.exe -c "C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test/main.cpp" -std=c++14 -Wall -g -O0 -Wall -o ./Debug/main.cpp.o -I. -I"C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\eigen-3.3.9" -I"C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\Halton" -I"C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\quasimvnrnd" -I"C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\dirent\dirent-master\include"
In file included from C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test/main.cpp:5:
C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\eigen-3.3.9/unsupported/Eigen/CXX11/Tensor:53:17: error: conflicting declaration 'typedef long int int32_t'
typedef __int32 int32_t;
^~~~~~~
In file included from c:\mingw\lib\gcc\mingw32\8.2.0\include\stdint.h:9,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\cstdint:41,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\bits\char_traits.h:501,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ios:40,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ostream:38,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\iostream:39,
from C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test/main.cpp:2:
c:\mingw\include\stdint.h:62:15: note: previous declaration as 'typedef int int32_t'
typedef int int32_t;
^~~~~~~
In file included from C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test/main.cpp:5:
C:\Users\RS3\Desktop\SCC HiWi\Code\C++\myGmm\UQ\eigen-3.3.9/unsupported/Eigen/CXX11/Tensor:54:26: error: conflicting declaration 'typedef long unsigned int uint32_t'
typedef unsigned __int32 uint32_t;
^~~~~~~~
In file included from c:\mingw\lib\gcc\mingw32\8.2.0\include\stdint.h:9,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\cstdint:41,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\bits\char_traits.h:501,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ios:40,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\ostream:38,
from c:\mingw\lib\gcc\mingw32\8.2.0\include\c++\iostream:39,
from C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test/main.cpp:2:
c:\mingw\include\stdint.h:63:19: note: previous declaration as 'typedef unsigned int uint32_t'
typedef unsigned uint32_t;
^~~~~~~~
mingw32-make.exe[1]: *** [Debug/main.cpp.o] Error 1
Test.mk:97: recipe for target 'Debug/main.cpp.o' failed
mingw32-make.exe[1]: Leaving directory 'C:/Users/RS3/Desktop/SCC HiWi/Code/C++/myGmm/UQ/Test'
mingw32-make.exe: *** [All] Error 2
Makefile:4: recipe for target 'All' failed
====1 errors, 4 warnings====
UPDATE: When I remove the last include and do the Eigen matrix again, there's no problem. So the problem is with the last include. But without it, I can't work with tensors. What should I do to work with tensors without the error?

Answer 1

Can you let us know where your version of MinGW comes from?
The issue is that your version of MinGW is apparently defining __int32 as long but int32_t as int, leading to a type conflict. We had some code in the Tensor module to ensure int32_t is always defined on Windows, since Visual Studio prior to 2010 doesn't actually provide an stdint.h header. We've never seen this cause an issue before. I tried several versions of MinGW, both 32-bit and 64-bit, but in all the ones I've tried so far __int32 is always an int.
I have a potential fix pending on the master branch here: !373. Once it's merged we can backport the change to the stable 3.3 branch.
If you just want to get something up and running, you can try installing a different version of MinGW.