Implement P0030R1: Introduce a 3-Argument Overload to std::hypot

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@269772 91177308-0d34-0410-b5e6-96231b3b80d8

include/cmath

@@ -209,6 +209,10 @@ floating_point hypot (arithmetic x, arithmetic y);
 float          hypotf(float x, float y);
 long double    hypotl(long double x, long double y);
 
+double       hypot(double x, double y, double z);                // C++17
+float        hypot(float x, float y, float z);                   // C++17
+long double  hypot(long double x, long double y, long double z); // C++17
+
 int ilogb (arithmetic x);
 int ilogbf(float x);
 int ilogbl(long double x);
@@ -548,6 +552,30 @@ using ::lgamma;
 using ::lgammaf;
 #endif // __sun__
 
+#if _LIBCPP_STD_VER > 14
+inline _LIBCPP_INLINE_VISIBILITY float       hypot(       float x,       float y,       float z ) { return sqrt(x*x + y*y + z*z); }
+inline _LIBCPP_INLINE_VISIBILITY double      hypot(      double x,      double y,      double z ) { return sqrt(x*x + y*y + z*z); }
+inline _LIBCPP_INLINE_VISIBILITY long double hypot( long double x, long double y, long double z ) { return sqrt(x*x + y*y + z*z); }
+
+template <class _A1, class _A2, class _A3>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::__lazy_enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value &&
+    std::is_arithmetic<_A3>::value,
+    std::__promote<_A1, _A2, _A3>
+>::type
+hypot(_A1 __lcpp_x, _A2 __lcpp_y, _A3 __lcpp_z) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2, _A3>::type __result_type;
+    static_assert((!(std::is_same<_A1, __result_type>::value &&
+                     std::is_same<_A2, __result_type>::value &&
+                     std::is_same<_A3, __result_type>::value)), "");
+    return hypot((__result_type)__lcpp_x, (__result_type)__lcpp_y, (__result_type)__lcpp_z);
+}
+#endif
+
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_CMATH

test/std/numerics/c.math/cmath.pass.cpp

@@ -79,6 +79,7 @@ Ambiguous fma(Ambiguous, Ambiguous, Ambiguous){ return Ambiguous(); }
 Ambiguous fmax(Ambiguous, Ambiguous){ return Ambiguous(); }
 Ambiguous fmin(Ambiguous, Ambiguous){ return Ambiguous(); }
 Ambiguous hypot(Ambiguous, Ambiguous){ return Ambiguous(); }
+Ambiguous hypot(Ambiguous, Ambiguous, Ambiguous){ return Ambiguous(); }
 Ambiguous ilogb(Ambiguous){ return Ambiguous(); }
 Ambiguous lgamma(Ambiguous){ return Ambiguous(); }
 Ambiguous llrint(Ambiguous){ return Ambiguous(); }
@@ -1010,6 +1011,28 @@ void test_hypot()
     static_assert((std::is_same<decltype(std::hypot((int)0, (int)0)), double>::value), "");
     static_assert((std::is_same<decltype(hypot(Ambiguous(), Ambiguous())), Ambiguous>::value), "");
     assert(std::hypot(3,4) == 5);
+    
+#if TEST_STD_VER > 14
+    static_assert((std::is_same<decltype(std::hypot((float)0, (float)0, (float)0)), float>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (bool)0, (float)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (unsigned short)0, (double)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (int)0, (long double)0)), long double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (unsigned int)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (double)0, (long)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (long double)0, (unsigned long)0)), long double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (int)0, (long long)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (int)0, (unsigned long long)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (double)0, (double)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (long double)0, (long double)0)), long double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (float)0, (double)0)), double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (float)0, (long double)0)), long double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((float)0, (double)0, (long double)0)), long double>::value), "");
+    static_assert((std::is_same<decltype(std::hypot((int)0, (int)0, (int)0)), double>::value), "");
+    static_assert((std::is_same<decltype(hypot(Ambiguous(), Ambiguous(), Ambiguous())), Ambiguous>::value), "");
+
+    assert(std::hypot(2,3,6) == 7);
+    assert(std::hypot(1,4,8) == 9);
+#endif
 }
 
 void test_ilogb()

www/cxx1z_status.html

@@ -89,7 +89,7 @@
 	<tr><td><a href="http://wg21.link/P0253R1">P0253R1</a></td><td>LWG</td><td>Fixing a design mistake in the searchers interface</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
 	<tr><td><a href="http://wg21.link/P0025R0">P0025R0</a></td><td>LWG</td><td>An algorithm to "clamp" a value between a pair of boundary values</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
 	<tr><td><a href="http://wg21.link/P0154R1">P0154R1</a></td><td>LWG</td><td>constexpr std::hardware_{constructive,destructive}_interference_size</td><td>Jacksonville</td><td></td><td></td></tr>
-	<tr><td><a href="http://wg21.link/P0030R1">P0030R1</a></td><td>LWG</td><td>Proposal to Introduce a 3-Argument Overload to std::hypot</td><td>Jacksonville</td><td></td><td></td></tr>
+	<tr><td><a href="http://wg21.link/P0030R1">P0030R1</a></td><td>LWG</td><td>Proposal to Introduce a 3-Argument Overload to std::hypot</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
 	<tr><td><a href="http://wg21.link/P0031R0">P0031R0</a></td><td>LWG</td><td>A Proposal to Add Constexpr Modifiers to reverse_iterator, move_iterator, array and Range Access</td><td>Jacksonville</td><td></td><td></td></tr>
 	<tr><td><a href="http://wg21.link/P0272R1">P0272R1</a></td><td>LWG</td><td>Give <tt>std::string</tt> a non-const <tt>.data()</tt> member function</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>
 	<tr><td><a href="http://wg21.link/P0077R2">P0077R2</a></td><td>LWG</td><td><tt>is_callable</tt>, the missing INVOKE related trait</td><td>Jacksonville</td><td>Complete</td><td>3.9</td></tr>