undeclared variable in flann/lsh_table.h with -std=gnu++0x (Bug #2179)

if you faced with a problem like this;

/usr/local/opencv/include/opencv2/flann/lsh_index.h:49:0,

                 from /usr/local/opencv/include/opencv2/flann/all_indices.h:42,

                 from /usr/local/opencv/include/opencv2/flann/flann_base.hpp:44,

                 from /usr/local/opencv/include/opencv2/flann/flann.hpp:50,

                 from /usr/local/opencv/include/opencv/cv.h:69,

                 from FlannMatchWindows.cpp:7:

/usr/local/opencv/include/opencv2/flann/lsh_table.h: In member function ‘void cvflann::lsh::LshTable<ElementType>::add(cvflann::Matrix<T>)’:

/usr/local/opencv/include/opencv2/flann/lsh_table.h:196:14: error: ‘use_speed_’ was not declared in this scope

this then you can check this link out and even though they do not say the fix you can find it here;

remove the statement "if (!use_speed_)"  from the line 196 lsh_table.h

it is also fixed on later version of 2.4.2