View Compilation Error

In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cassert:43:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/x86_64-w64-mingw32/bits/stdc++.h:33,
                 from 0_0_37769260_25257.cpp:1:
0_0_37769260_25257.cpp: In function 'int main()':
0_0_37769260_25257.cpp:72:22: error: 'high_bit' was not declared in this scope
     assert(high_bit(u) == i);
                      ^