foo.cpp: In function 'int main()':
foo.cpp:18:12: error: invalid operands of types '__gnu_cxx::__enable_if<true, double>::__type {aka double}' and 'long long int' to binary 'operator%'
  ou=abs(x)%b;
            ^
foo.cpp:16:12: warning: unused variable 'i' [-Wunused-variable]
  long long i;
            ^