This is the mail archive of the
libstdc++@gcc.gnu.org
mailing list for the libstdc++ project.
Re: [PATCH] Define 3-argument overloads of std::hypot for C++17 (P0030R1)
On 29/09/16 11:47 +0100, Jonathan Wakely wrote:
On 29/09/16 12:39 +0200, Rainer Orth wrote:
Hi Jonathan,
That would suggest Solaris uses include/c_std/cmath (where I forgot to
add the new overloads) rather than include/c_global/cmath ... is that
right?
Alternatively it's using c_global/cmath but _GLIBCXX_USE_C99_MATH_TR1
is not defined, as the new overloads are inside that block. I thought
that was defined for Solaris though, which is why we have the
__CORRECT_ISO_CPP11_MATH_H_PROTO there in that file.
it is indeed, at least initially. What I see in preprocessed input is
this:
ro@galeras 208 > grep _GLIBCXX_USE_C99_MATH testsuite/normal4/hypot.ii
#define _GLIBCXX_USE_C99_MATH _GLIBCXX11_USE_C99_MATH
#define _GLIBCXX_USE_C99_MATH_TR1 1
#undef _GLIBCXX_USE_C99_MATH
#undef _GLIBCXX_USE_C99_MATH_TR1
It turns out the #undef's are from <math.h>:
#if __cplusplus >= 201103L
#undef _GLIBCXX_USE_C99_MATH
#undef _GLIBCXX_USE_C99_MATH_TR1
#endif
No idea what this nonsense is trying to accomplish! It's already in
Solaris 11.3, however.
Wow.
If only there was some way the Solaris team could contact us so we
could coordinate and stop adding more and more hacks to mess with each
others headers. But I assume they don't have access to the www or
email, because the only other explanation is too rude to say on a
public list.
Presumably they now provide all the declarations for C++11, so we
don't need to declare them. Moving the new hypot overload outside the
_GLIBCXX_USE_C99_MATH_TR1 block should mean it's declared. That will
break when Solaris adds C++17 support, so we'd better add some macro
to guard the new hypot overloads, so they can be disabled again. Let's
call it __CORRECT_ISO_CPP17_MATH_H_PROTO (and maybe add a coment like
"Dear Solaris team, ...").
Does this work?
diff --git a/libstdc++-v3/include/c_global/cmath b/libstdc++-v3/include/c_global/cmath
index fffa0e7..86ffd34 100644
--- a/libstdc++-v3/include/c_global/cmath
+++ b/libstdc++-v3/include/c_global/cmath
@@ -1455,46 +1455,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
return hypot(__type(__x), __type(__y));
}
-#if __cplusplus > 201402L
-#define __cpp_lib_hypot 201603
- // [c.math.hypot3], three-dimensional hypotenuse
-
- template<typename _Tp>
- inline _Tp
- __hypot3(_Tp __x, _Tp __y, _Tp __z)
- {
- __x = std::abs(__x);
- __y = std::abs(__y);
- __z = std::abs(__z);
- if (_Tp __a = __x < __y ? __y < __z ? __z : __y : __x < __z ? __z : __x)
- return __a * std::sqrt((__x / __a) * (__x / __a)
- + (__y / __a) * (__y / __a)
- + (__z / __a) * (__z / __a));
- else
- return {};
- }
-
- inline float
- hypot(float __x, float __y, float __z)
- { return std::__hypot3<float>(__x, __y, __z); }
-
- inline double
- hypot(double __x, double __y, double __z)
- { return std::__hypot3<double>(__x, __y, __z); }
-
- inline long double
- hypot(long double __x, long double __y, long double __z)
- { return std::__hypot3<long double>(__x, __y, __z); }
-
- template<typename _Tp, typename _Up, typename _Vp>
- typename __gnu_cxx::__promote_3<_Tp, _Up, _Vp>::__type
- hypot(_Tp __x, _Up __y, _Vp __z)
- {
- using __type = typename __gnu_cxx::__promote_3<_Tp, _Up, _Vp>::__type;
- return std::__hypot3<__type>(__x, __y, __z);
- }
-#endif // C++17
-
#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO
constexpr int
ilogb(float __x)
@@ -1830,6 +1790,55 @@ _GLIBCXX_END_NAMESPACE_VERSION
#endif // C++11
+#if __cplusplus > 201402L
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+#ifndef __CORRECT_ISO_CPP17_MATH_H_PROTO
+ // [c.math.hypot3], three-dimensional hypotenuse
+#define __cpp_lib_hypot 201603
+
+ template<typename _Tp>
+ inline _Tp
+ __hypot3(_Tp __x, _Tp __y, _Tp __z)
+ {
+ __x = std::abs(__x);
+ __y = std::abs(__y);
+ __z = std::abs(__z);
+ if (_Tp __a = __x < __y ? __y < __z ? __z : __y : __x < __z ? __z : __x)
+ return __a * std::sqrt((__x / __a) * (__x / __a)
+ + (__y / __a) * (__y / __a)
+ + (__z / __a) * (__z / __a));
+ else
+ return {};
+ }
+
+ inline float
+ hypot(float __x, float __y, float __z)
+ { return std::__hypot3<float>(__x, __y, __z); }
+
+ inline double
+ hypot(double __x, double __y, double __z)
+ { return std::__hypot3<double>(__x, __y, __z); }
+
+ inline long double
+ hypot(long double __x, long double __y, long double __z)
+ { return std::__hypot3<long double>(__x, __y, __z); }
+
+ template<typename _Tp, typename _Up, typename _Vp>
+ typename __gnu_cxx::__promote_3<_Tp, _Up, _Vp>::__type
+ hypot(_Tp __x, _Up __y, _Vp __z)
+ {
+ using __type = typename __gnu_cxx::__promote_3<_Tp, _Up, _Vp>::__type;
+ return std::__hypot3<__type>(__x, __y, __z);
+#endif
+ }
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+#endif // C++17
+
+
#if _GLIBCXX_USE_STD_SPEC_FUNCS
# include <bits/specfun.h>
#endif