USE_UNORDERED_MAP define should be protected by "namespace"

[fps]

e.g.

FLANN_USE_UNORDERED_MAP

We had a mysterious error in the serialization code if we included the flann headers after some opencv headers and used g++ -std=c++11. Changing the include order fixed the issue (including flann headers before any opencv headers). It seems that opencv headers leak #define USE_UNORDERED_MAP 1 in case of std >= c++0x. This then gets picked up by the #if in lsh_table.h in the original flann library.

[ahmadhasan2k8]

+1