In file included from /in/Compile/check.cpp:7:
/in/sokoban.hpp:345:42: error: use of undeclared identifier 'log2'
        roots.assign(static_cast<size_t>(log2(size) * 2), nullptr);
                                         ^
/in/sokoban.hpp:358:26: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
            while (roots[d]) {
                   ~~~~~ ^
/in/sokoban.hpp:359:36: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
                FibNode* y = roots[d];
                             ~~~~~ ^
/in/sokoban.hpp:364:23: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
                roots[d] = nullptr;
                ~~~~~ ^
/in/sokoban.hpp:367:19: error: implicit conversion changes signedness: 'int' to 'std::vector::size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
            roots[d] = node;
            ~~~~~ ^
5 errors generated.
/in/Compile/Makefile:16: recipe for target 'main' failed
make: *** [main] Error 1