/in/foo.cc: In function 'void fft(Complex*, int, int)':
/in/foo.cc:32:16: error: 'cos' was not declared in this scope
  wn={cos(2*PI/n),d*sin(2*PI/n)};
                ^
/in/foo.cc:32:30: error: 'sin' was not declared in this scope
  wn={cos(2*PI/n),d*sin(2*PI/n)};
                              ^
/in/foo.cc:32:31: error: no match for 'operator=' (operand types are 'Complex' and '<brace-enclosed initializer list>')
  wn={cos(2*PI/n),d*sin(2*PI/n)};
                               ^
/in/foo.cc:5:8: note: candidate: Complex& Complex::operator=(const Complex&)
 struct Complex
        ^~~~~~~
/in/foo.cc:5:8: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const Complex&'
/in/foo.cc:5:8: note: candidate: Complex& Complex::operator=(Complex&&)
/in/foo.cc:5:8: note:   no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'Complex&&'
/in/foo.cc: In function 'int main()':
/in/foo.cc:48:41: error: 'log2' was not declared in this scope
  int len = 1 << max((int)ceil(log2(n + m)), 1);
                                         ^
/in/foo.cc:48:42: error: 'ceil' was not declared in this scope
  int len = 1 << max((int)ceil(log2(n + m)), 1);
                                          ^
/in/foo.cc:48:46: error: 'max' was not declared in this scope
  int len = 1 << max((int)ceil(log2(n + m)), 1);
                                              ^