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[Bug libstdc++/61761] [C++11] std::proj returns incorrect values
- From: "redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 09 Apr 2015 15:41:55 +0000
- Subject: [Bug libstdc++/61761] [C++11] std::proj returns incorrect values
- Auto-submitted: auto-generated
- References: <bug-61761-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61761
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2015-04-09
Ever confirmed|0 |1
Severity|normal |minor
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I suppose something like this isn't usable because it won't work unless _Tp is
float, double or long double:
--- a/libstdc++-v3/include/std/complex
+++ b/libstdc++-v3/include/std/complex
@@ -1887,11 +1887,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
std::complex<_Tp>
__complex_proj(const std::complex<_Tp>& __z)
{
- const _Tp __den = (__z.real() * __z.real()
- + __z.imag() * __z.imag() + _Tp(1.0));
-
- return std::complex<_Tp>((_Tp(2.0) * __z.real()) / __den,
- (_Tp(2.0) * __z.imag()) / __den);
+ if (isinf(__z.real()) || isinf(__z.imag())
+ || isnan(__z.real()) || isnan(__z.imag()))
+ return std::complex<_Tp>(INFINITY, copysign(0.0, __z.imag()));
+ return __z;
}
#if _GLIBCXX_USE_C99_COMPLEX