#pragma GCC system_header
#include <bits/c++config.h>
+#include <bits/cpp_type_traits.h>
#include <bits/std_cmath.h>
#include <bits/std_sstream.h>
arg(const complex<_Tp>& __z)
{ return atan2(__z.imag(), __z.real()); }
+ // 26.2.7/5: norm(__z) returns the squared magintude of __z.
+ // As defined, norm() is -not- a norm is the common mathematical
+ // sens used in numerics. The helper class _Norm_helper<> tries to
+ // distinguish between builtin floating point and the rest, so as
+ // to deliver an answer as close as possible to the real value.
+ template<bool>
+ struct _Norm_helper
+ {
+ template<typename _Tp>
+ static inline _Tp _S_do_it(const complex<_Tp>& __z)
+ {
+ const _Tp __x = __z.real();
+ const _Tp __y = __z.imag();
+ return __x * __x + __y * __y;
+ }
+ };
+
+ template<>
+ struct _Norm_helper<true>
+ {
+ template<typename _Tp>
+ static inline _Tp _S_do_it(const complex<_Tp>& __z)
+ {
+ _Tp __res = abs(__z);
+ return __res * __res;
+ }
+ };
+
template<typename _Tp>
inline _Tp
norm(const complex<_Tp>& __z)
{
- _Tp __res = abs(__z);
- return __res * __res;
+ return _Norm_helper<__is_floating<_Tp>::_M_type>::_S_do_it(__z);
}
template<typename _Tp>