In file included from /usr/include/c++/4.4/unordered_map:35, from poze.cpp:4: /usr/include/c++/4.4/c++0x_warning.h:31:2: error: #error This file requires compiler and library support for the upcoming ISO C++ standard, C++0x. This support is currently experimental, and must be enabled with the -std=c++0x or -std=gnu++0x compiler options. poze.cpp:8: error: '>>' should be '> >' within a nested template argument list poze.cpp:17: error: '>>' should be '> >' within a nested template argument list poze.cpp: In function 'bool checkSquare(const std::vector<std::vector<int, std::allocator<int> >, std::allocator<std::vector<int, std::allocator<int> > > >&, int, int, int, int)': poze.cpp:19: error: 'unordered_map' was not declared in this scope poze.cpp:19: error: expected primary-expression before 'long' poze.cpp:19: error: expected ';' before 'long' poze.cpp:28: error: 'hashCount' was not declared in this scope poze.cpp: At global scope: poze.cpp:36: error: '>>' should be '> >' within a nested template argument list poze.cpp: In function 'int main()': poze.cpp:63: error: '>>' should be '> >' within a nested template argument list