View Compilation Error

0_0_38545212_1642.cpp: In function 'int main()':
0_0_38545212_1642.cpp:5:14: error: invalid operands of types '__gnu_cxx::__enable_if<true, double>::__type {aka double}' and 'const char [2]' to binary 'operator<<'
 #define endl "\n"
              ^
0_0_38545212_1642.cpp:23:38: note: in expansion of macro 'endl'
   int ans = k * (1 + sqrt(5)) / 2 << endl;
                                      ^