diff --git a/libcxx/include/cmath b/libcxx/include/cmath
--- a/libcxx/include/cmath
+++ b/libcxx/include/cmath
@@ -328,153 +328,83 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-using ::signbit _LIBCPP_USING_IF_EXISTS;
-using ::fpclassify _LIBCPP_USING_IF_EXISTS;
-using ::isfinite _LIBCPP_USING_IF_EXISTS;
-using ::isinf _LIBCPP_USING_IF_EXISTS;
-using ::isnan _LIBCPP_USING_IF_EXISTS;
-using ::isnormal _LIBCPP_USING_IF_EXISTS;
-using ::isgreater _LIBCPP_USING_IF_EXISTS;
-using ::isgreaterequal _LIBCPP_USING_IF_EXISTS;
-using ::isless _LIBCPP_USING_IF_EXISTS;
-using ::islessequal _LIBCPP_USING_IF_EXISTS;
-using ::islessgreater _LIBCPP_USING_IF_EXISTS;
-using ::isunordered _LIBCPP_USING_IF_EXISTS;
-using ::isunordered _LIBCPP_USING_IF_EXISTS;
-
 using ::float_t _LIBCPP_USING_IF_EXISTS;
 using ::double_t _LIBCPP_USING_IF_EXISTS;
 
 using ::abs _LIBCPP_USING_IF_EXISTS;
 
-using ::acos _LIBCPP_USING_IF_EXISTS;
 using ::acosf _LIBCPP_USING_IF_EXISTS;
-using ::asin _LIBCPP_USING_IF_EXISTS;
 using ::asinf _LIBCPP_USING_IF_EXISTS;
-using ::atan _LIBCPP_USING_IF_EXISTS;
 using ::atanf _LIBCPP_USING_IF_EXISTS;
-using ::atan2 _LIBCPP_USING_IF_EXISTS;
 using ::atan2f _LIBCPP_USING_IF_EXISTS;
-using ::ceil _LIBCPP_USING_IF_EXISTS;
 using ::ceilf _LIBCPP_USING_IF_EXISTS;
-using ::cos _LIBCPP_USING_IF_EXISTS;
 using ::cosf _LIBCPP_USING_IF_EXISTS;
-using ::cosh _LIBCPP_USING_IF_EXISTS;
 using ::coshf _LIBCPP_USING_IF_EXISTS;
 
-using ::exp _LIBCPP_USING_IF_EXISTS;
 using ::expf _LIBCPP_USING_IF_EXISTS;
 
-using ::fabs _LIBCPP_USING_IF_EXISTS;
 using ::fabsf _LIBCPP_USING_IF_EXISTS;
-using ::floor _LIBCPP_USING_IF_EXISTS;
 using ::floorf _LIBCPP_USING_IF_EXISTS;
 
-using ::fmod _LIBCPP_USING_IF_EXISTS;
 using ::fmodf _LIBCPP_USING_IF_EXISTS;
 
-using ::frexp _LIBCPP_USING_IF_EXISTS;
 using ::frexpf _LIBCPP_USING_IF_EXISTS;
-using ::ldexp _LIBCPP_USING_IF_EXISTS;
 using ::ldexpf _LIBCPP_USING_IF_EXISTS;
 
-using ::log _LIBCPP_USING_IF_EXISTS;
 using ::logf _LIBCPP_USING_IF_EXISTS;
 
-using ::log10 _LIBCPP_USING_IF_EXISTS;
 using ::log10f _LIBCPP_USING_IF_EXISTS;
-using ::modf _LIBCPP_USING_IF_EXISTS;
 using ::modff _LIBCPP_USING_IF_EXISTS;
 
-using ::pow _LIBCPP_USING_IF_EXISTS;
 using ::powf _LIBCPP_USING_IF_EXISTS;
 
-using ::sin _LIBCPP_USING_IF_EXISTS;
 using ::sinf _LIBCPP_USING_IF_EXISTS;
-using ::sinh _LIBCPP_USING_IF_EXISTS;
 using ::sinhf _LIBCPP_USING_IF_EXISTS;
 
-using ::sqrt _LIBCPP_USING_IF_EXISTS;
 using ::sqrtf _LIBCPP_USING_IF_EXISTS;
-using ::tan _LIBCPP_USING_IF_EXISTS;
 using ::tanf _LIBCPP_USING_IF_EXISTS;
 
-using ::tanh _LIBCPP_USING_IF_EXISTS;
 using ::tanhf _LIBCPP_USING_IF_EXISTS;
 
-using ::acosh _LIBCPP_USING_IF_EXISTS;
 using ::acoshf _LIBCPP_USING_IF_EXISTS;
-using ::asinh _LIBCPP_USING_IF_EXISTS;
 using ::asinhf _LIBCPP_USING_IF_EXISTS;
-using ::atanh _LIBCPP_USING_IF_EXISTS;
 using ::atanhf _LIBCPP_USING_IF_EXISTS;
-using ::cbrt _LIBCPP_USING_IF_EXISTS;
 using ::cbrtf _LIBCPP_USING_IF_EXISTS;
 
-using ::copysign _LIBCPP_USING_IF_EXISTS;
 using ::copysignf _LIBCPP_USING_IF_EXISTS;
 
-using ::erf _LIBCPP_USING_IF_EXISTS;
 using ::erff _LIBCPP_USING_IF_EXISTS;
-using ::erfc _LIBCPP_USING_IF_EXISTS;
 using ::erfcf _LIBCPP_USING_IF_EXISTS;
-using ::exp2 _LIBCPP_USING_IF_EXISTS;
 using ::exp2f _LIBCPP_USING_IF_EXISTS;
-using ::expm1 _LIBCPP_USING_IF_EXISTS;
 using ::expm1f _LIBCPP_USING_IF_EXISTS;
-using ::fdim _LIBCPP_USING_IF_EXISTS;
 using ::fdimf _LIBCPP_USING_IF_EXISTS;
 using ::fmaf _LIBCPP_USING_IF_EXISTS;
-using ::fma _LIBCPP_USING_IF_EXISTS;
-using ::fmax _LIBCPP_USING_IF_EXISTS;
 using ::fmaxf _LIBCPP_USING_IF_EXISTS;
-using ::fmin _LIBCPP_USING_IF_EXISTS;
 using ::fminf _LIBCPP_USING_IF_EXISTS;
-using ::hypot _LIBCPP_USING_IF_EXISTS;
 using ::hypotf _LIBCPP_USING_IF_EXISTS;
-using ::ilogb _LIBCPP_USING_IF_EXISTS;
 using ::ilogbf _LIBCPP_USING_IF_EXISTS;
-using ::lgamma _LIBCPP_USING_IF_EXISTS;
 using ::lgammaf _LIBCPP_USING_IF_EXISTS;
-using ::llrint _LIBCPP_USING_IF_EXISTS;
 using ::llrintf _LIBCPP_USING_IF_EXISTS;
-using ::llround _LIBCPP_USING_IF_EXISTS;
 using ::llroundf _LIBCPP_USING_IF_EXISTS;
-using ::log1p _LIBCPP_USING_IF_EXISTS;
 using ::log1pf _LIBCPP_USING_IF_EXISTS;
-using ::log2 _LIBCPP_USING_IF_EXISTS;
 using ::log2f _LIBCPP_USING_IF_EXISTS;
-using ::logb _LIBCPP_USING_IF_EXISTS;
 using ::logbf _LIBCPP_USING_IF_EXISTS;
-using ::lrint _LIBCPP_USING_IF_EXISTS;
 using ::lrintf _LIBCPP_USING_IF_EXISTS;
-using ::lround _LIBCPP_USING_IF_EXISTS;
 using ::lroundf _LIBCPP_USING_IF_EXISTS;
 
 using ::nan _LIBCPP_USING_IF_EXISTS;
 using ::nanf _LIBCPP_USING_IF_EXISTS;
 
-using ::nearbyint _LIBCPP_USING_IF_EXISTS;
 using ::nearbyintf _LIBCPP_USING_IF_EXISTS;
-using ::nextafter _LIBCPP_USING_IF_EXISTS;
 using ::nextafterf _LIBCPP_USING_IF_EXISTS;
-using ::nexttoward _LIBCPP_USING_IF_EXISTS;
 using ::nexttowardf _LIBCPP_USING_IF_EXISTS;
-using ::remainder _LIBCPP_USING_IF_EXISTS;
 using ::remainderf _LIBCPP_USING_IF_EXISTS;
-using ::remquo _LIBCPP_USING_IF_EXISTS;
 using ::remquof _LIBCPP_USING_IF_EXISTS;
-using ::rint _LIBCPP_USING_IF_EXISTS;
 using ::rintf _LIBCPP_USING_IF_EXISTS;
-using ::round _LIBCPP_USING_IF_EXISTS;
 using ::roundf _LIBCPP_USING_IF_EXISTS;
-using ::scalbln _LIBCPP_USING_IF_EXISTS;
 using ::scalblnf _LIBCPP_USING_IF_EXISTS;
-using ::scalbn _LIBCPP_USING_IF_EXISTS;
 using ::scalbnf _LIBCPP_USING_IF_EXISTS;
-using ::tgamma _LIBCPP_USING_IF_EXISTS;
 using ::tgammaf _LIBCPP_USING_IF_EXISTS;
-using ::trunc _LIBCPP_USING_IF_EXISTS;
 using ::truncf _LIBCPP_USING_IF_EXISTS;
 
 using ::acosl _LIBCPP_USING_IF_EXISTS;
diff --git a/libcxx/include/math.h b/libcxx/include/math.h
--- a/libcxx/include/math.h
+++ b/libcxx/include/math.h
@@ -310,6 +310,8 @@
 #include <stdlib.h>
 #include <type_traits>
 
+_LIBCPP_BEGIN_NAMESPACE_STD
+
 // signbit
 
 #ifdef signbit
@@ -791,6 +793,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       acos(float __x) _NOEXCEPT       {return ::acosf(__x);}
+using ::acos _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double acos(long double __x) _NOEXCEPT {return ::acosl(__x);}
 #    endif
 
@@ -803,6 +806,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       asin(float __x) _NOEXCEPT       {return ::asinf(__x);}
+using ::asin _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double asin(long double __x) _NOEXCEPT {return ::asinl(__x);}
 #    endif
 
@@ -815,6 +819,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       atan(float __x) _NOEXCEPT       {return ::atanf(__x);}
+using ::atan _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double atan(long double __x) _NOEXCEPT {return ::atanl(__x);}
 #    endif
 
@@ -827,6 +832,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       atan2(float __y, float __x) _NOEXCEPT             {return ::atan2f(__y, __x);}
+using ::atan2 _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double atan2(long double __y, long double __x) _NOEXCEPT {return ::atan2l(__y, __x);}
 #    endif
 
@@ -850,6 +856,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       ceil(float __x) _NOEXCEPT       {return ::ceilf(__x);}
+using ::ceil _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double ceil(long double __x) _NOEXCEPT {return ::ceill(__x);}
 #    endif
 
@@ -862,6 +869,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       cos(float __x) _NOEXCEPT       {return ::cosf(__x);}
+using ::cos _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double cos(long double __x) _NOEXCEPT {return ::cosl(__x);}
 #    endif
 
@@ -874,6 +882,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       cosh(float __x) _NOEXCEPT       {return ::coshf(__x);}
+using ::cosh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double cosh(long double __x) _NOEXCEPT {return ::coshl(__x);}
 #    endif
 
@@ -886,6 +895,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       exp(float __x) _NOEXCEPT       {return ::expf(__x);}
+using ::exp _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double exp(long double __x) _NOEXCEPT {return ::expl(__x);}
 #    endif
 
@@ -898,6 +908,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       fabs(float __x) _NOEXCEPT       {return ::fabsf(__x);}
+using ::fabs _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double fabs(long double __x) _NOEXCEPT {return ::fabsl(__x);}
 #    endif
 
@@ -910,6 +921,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       floor(float __x) _NOEXCEPT       {return ::floorf(__x);}
+using ::floor _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double floor(long double __x) _NOEXCEPT {return ::floorl(__x);}
 #    endif
 
@@ -922,6 +934,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       fmod(float __x, float __y) _NOEXCEPT             {return ::fmodf(__x, __y);}
+using ::fmod _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double fmod(long double __x, long double __y) _NOEXCEPT {return ::fmodl(__x, __y);}
 #    endif
 
@@ -945,6 +958,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       frexp(float __x, int* __e) _NOEXCEPT       {return ::frexpf(__x, __e);}
+using ::frexp _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double frexp(long double __x, int* __e) _NOEXCEPT {return ::frexpl(__x, __e);}
 #    endif
 
@@ -957,6 +971,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       ldexp(float __x, int __e) _NOEXCEPT       {return ::ldexpf(__x, __e);}
+using ::ldexp _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double ldexp(long double __x, int __e) _NOEXCEPT {return ::ldexpl(__x, __e);}
 #    endif
 
@@ -969,6 +984,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       log(float __x) _NOEXCEPT       {return ::logf(__x);}
+using ::log _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double log(long double __x) _NOEXCEPT {return ::logl(__x);}
 #    endif
 
@@ -981,6 +997,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       log10(float __x) _NOEXCEPT       {return ::log10f(__x);}
+using ::log10 _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double log10(long double __x) _NOEXCEPT {return ::log10l(__x);}
 #    endif
 
@@ -993,6 +1010,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       modf(float __x, float* __y) _NOEXCEPT             {return ::modff(__x, __y);}
+using ::modf _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double modf(long double __x, long double* __y) _NOEXCEPT {return ::modfl(__x, __y);}
 #    endif
 
@@ -1000,6 +1018,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       pow(float __x, float __y) _NOEXCEPT             {return ::powf(__x, __y);}
+using ::pow _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double pow(long double __x, long double __y) _NOEXCEPT {return ::powl(__x, __y);}
 #    endif
 
@@ -1023,6 +1042,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sin(float __x) _NOEXCEPT       {return ::sinf(__x);}
+using ::sin _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double sin(long double __x) _NOEXCEPT {return ::sinl(__x);}
 #endif
 
@@ -1035,6 +1055,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sinh(float __x) _NOEXCEPT       {return ::sinhf(__x);}
+using ::sinh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double sinh(long double __x) _NOEXCEPT {return ::sinhl(__x);}
 #    endif
 
@@ -1047,6 +1068,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sqrt(float __x) _NOEXCEPT       {return ::sqrtf(__x);}
+using ::sqrt _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double sqrt(long double __x) _NOEXCEPT {return ::sqrtl(__x);}
 #    endif
 
@@ -1059,6 +1081,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       tan(float __x) _NOEXCEPT       {return ::tanf(__x);}
+using ::tan _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double tan(long double __x) _NOEXCEPT {return ::tanl(__x);}
 #    endif
 
@@ -1071,6 +1094,7 @@
 
 #    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       tanh(float __x) _NOEXCEPT       {return ::tanhf(__x);}
+using ::tanh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double tanh(long double __x) _NOEXCEPT {return ::tanhl(__x);}
 #    endif
 
@@ -1082,6 +1106,7 @@
 // acosh
 
 inline _LIBCPP_HIDE_FROM_ABI float       acosh(float __x) _NOEXCEPT       {return ::acoshf(__x);}
+using ::acosh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double acosh(long double __x) _NOEXCEPT {return ::acoshl(__x);}
 
 template <class _A1>
@@ -1092,6 +1117,7 @@
 // asinh
 
 inline _LIBCPP_HIDE_FROM_ABI float       asinh(float __x) _NOEXCEPT       {return ::asinhf(__x);}
+using ::asinh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double asinh(long double __x) _NOEXCEPT {return ::asinhl(__x);}
 
 template <class _A1>
@@ -1102,6 +1128,7 @@
 // atanh
 
 inline _LIBCPP_HIDE_FROM_ABI float       atanh(float __x) _NOEXCEPT       {return ::atanhf(__x);}
+using ::atanh _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double atanh(long double __x) _NOEXCEPT {return ::atanhl(__x);}
 
 template <class _A1>
@@ -1112,6 +1139,7 @@
 // cbrt
 
 inline _LIBCPP_HIDE_FROM_ABI float       cbrt(float __x) _NOEXCEPT       {return ::cbrtf(__x);}
+using ::cbrt _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double cbrt(long double __x) _NOEXCEPT {return ::cbrtl(__x);}
 
 template <class _A1>
@@ -1177,11 +1205,13 @@
 }
 
 inline _LIBCPP_HIDE_FROM_ABI float copysign(float __x, float __y) _NOEXCEPT {
-  return ::__libcpp_copysign(__x, __y);
+  return std::__libcpp_copysign(__x, __y);
 }
 
+using ::copysign _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long double copysign(long double __x, long double __y) _NOEXCEPT {
-  return ::__libcpp_copysign(__x, __y);
+  return std::__libcpp_copysign(__x, __y);
 }
 
 template <class _A1, class _A2>
@@ -1193,12 +1223,13 @@
     std::__promote<_A1, _A2>
 >::type
     copysign(_A1 __x, _A2 __y) _NOEXCEPT {
-  return ::__libcpp_copysign(__x, __y);
+  return std::__libcpp_copysign(__x, __y);
 }
 
 // erf
 
 inline _LIBCPP_HIDE_FROM_ABI float       erf(float __x) _NOEXCEPT       {return ::erff(__x);}
+using ::erf _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double erf(long double __x) _NOEXCEPT {return ::erfl(__x);}
 
 template <class _A1>
@@ -1209,6 +1240,7 @@
 // erfc
 
 inline _LIBCPP_HIDE_FROM_ABI float       erfc(float __x) _NOEXCEPT       {return ::erfcf(__x);}
+using ::erfc _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double erfc(long double __x) _NOEXCEPT {return ::erfcl(__x);}
 
 template <class _A1>
@@ -1219,6 +1251,7 @@
 // exp2
 
 inline _LIBCPP_HIDE_FROM_ABI float       exp2(float __x) _NOEXCEPT       {return ::exp2f(__x);}
+using ::exp2 _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double exp2(long double __x) _NOEXCEPT {return ::exp2l(__x);}
 
 template <class _A1>
@@ -1229,6 +1262,7 @@
 // expm1
 
 inline _LIBCPP_HIDE_FROM_ABI float       expm1(float __x) _NOEXCEPT       {return ::expm1f(__x);}
+using ::expm1 _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double expm1(long double __x) _NOEXCEPT {return ::expm1l(__x);}
 
 template <class _A1>
@@ -1239,6 +1273,7 @@
 // fdim
 
 inline _LIBCPP_HIDE_FROM_ABI float       fdim(float __x, float __y) _NOEXCEPT             {return ::fdimf(__x, __y);}
+using ::fdim _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double fdim(long double __x, long double __y) _NOEXCEPT {return ::fdiml(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1267,6 +1302,9 @@
     return ::fmaf(__x, __y, __z);
 #endif
 }
+
+using ::fma _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long double fma(long double __x, long double __y, long double __z) _NOEXCEPT
 {
 #if __has_builtin(__builtin_fmal)
@@ -1301,6 +1339,7 @@
 // fmax
 
 inline _LIBCPP_HIDE_FROM_ABI float       fmax(float __x, float __y) _NOEXCEPT             {return ::fmaxf(__x, __y);}
+using ::fmax _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double fmax(long double __x, long double __y) _NOEXCEPT {return ::fmaxl(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1322,6 +1361,7 @@
 // fmin
 
 inline _LIBCPP_HIDE_FROM_ABI float       fmin(float __x, float __y) _NOEXCEPT             {return ::fminf(__x, __y);}
+using ::fmin _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double fmin(long double __x, long double __y) _NOEXCEPT {return ::fminl(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1343,6 +1383,7 @@
 // hypot
 
 inline _LIBCPP_HIDE_FROM_ABI float       hypot(float __x, float __y) _NOEXCEPT             {return ::hypotf(__x, __y);}
+using ::hypot _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double hypot(long double __x, long double __y) _NOEXCEPT {return ::hypotl(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1364,6 +1405,7 @@
 // ilogb
 
 inline _LIBCPP_HIDE_FROM_ABI int ilogb(float __x) _NOEXCEPT       {return ::ilogbf(__x);}
+using ::ilogb _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI int ilogb(long double __x) _NOEXCEPT {return ::ilogbl(__x);}
 
 template <class _A1>
@@ -1374,6 +1416,7 @@
 // lgamma
 
 inline _LIBCPP_HIDE_FROM_ABI float       lgamma(float __x) _NOEXCEPT       {return ::lgammaf(__x);}
+using ::lgamma _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double lgamma(long double __x) _NOEXCEPT {return ::lgammal(__x);}
 
 template <class _A1>
@@ -1391,6 +1434,9 @@
     return ::llrintf(__x);
 #endif
 }
+
+using ::llrint _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long long llrint(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_llrintl)
@@ -1422,6 +1468,9 @@
     return ::llroundf(__x);
 #endif
 }
+
+using ::llround _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long long llround(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_llroundl)
@@ -1446,6 +1495,7 @@
 // log1p
 
 inline _LIBCPP_HIDE_FROM_ABI float       log1p(float __x) _NOEXCEPT       {return ::log1pf(__x);}
+using ::log1p _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double log1p(long double __x) _NOEXCEPT {return ::log1pl(__x);}
 
 template <class _A1>
@@ -1456,6 +1506,7 @@
 // log2
 
 inline _LIBCPP_HIDE_FROM_ABI float       log2(float __x) _NOEXCEPT       {return ::log2f(__x);}
+using ::log2 _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double log2(long double __x) _NOEXCEPT {return ::log2l(__x);}
 
 template <class _A1>
@@ -1466,6 +1517,7 @@
 // logb
 
 inline _LIBCPP_HIDE_FROM_ABI float       logb(float __x) _NOEXCEPT       {return ::logbf(__x);}
+using ::logb _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double logb(long double __x) _NOEXCEPT {return ::logbl(__x);}
 
 template <class _A1>
@@ -1483,6 +1535,9 @@
     return ::lrintf(__x);
 #endif
 }
+
+using ::lrint _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long lrint(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_lrintl)
@@ -1514,6 +1569,9 @@
     return ::lroundf(__x);
 #endif
 }
+
+using ::lround _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long lround(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_lroundl)
@@ -1540,6 +1598,7 @@
 // nearbyint
 
 inline _LIBCPP_HIDE_FROM_ABI float       nearbyint(float __x) _NOEXCEPT       {return ::nearbyintf(__x);}
+using ::nearbyint _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double nearbyint(long double __x) _NOEXCEPT {return ::nearbyintl(__x);}
 
 template <class _A1>
@@ -1550,6 +1609,7 @@
 // nextafter
 
 inline _LIBCPP_HIDE_FROM_ABI float       nextafter(float __x, float __y) _NOEXCEPT             {return ::nextafterf(__x, __y);}
+using ::nextafter _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double nextafter(long double __x, long double __y) _NOEXCEPT {return ::nextafterl(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1571,6 +1631,7 @@
 // nexttoward
 
 inline _LIBCPP_HIDE_FROM_ABI float       nexttoward(float __x, long double __y) _NOEXCEPT       {return ::nexttowardf(__x, __y);}
+using ::nexttoward _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double nexttoward(long double __x, long double __y) _NOEXCEPT {return ::nexttowardl(__x, __y);}
 
 template <class _A1>
@@ -1581,6 +1642,7 @@
 // remainder
 
 inline _LIBCPP_HIDE_FROM_ABI float       remainder(float __x, float __y) _NOEXCEPT             {return ::remainderf(__x, __y);}
+using ::remainder _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double remainder(long double __x, long double __y) _NOEXCEPT {return ::remainderl(__x, __y);}
 
 template <class _A1, class _A2>
@@ -1602,6 +1664,7 @@
 // remquo
 
 inline _LIBCPP_HIDE_FROM_ABI float       remquo(float __x, float __y, int* __z) _NOEXCEPT             {return ::remquof(__x, __y, __z);}
+using ::remquo _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double remquo(long double __x, long double __y, int* __z) _NOEXCEPT {return ::remquol(__x, __y, __z);}
 
 template <class _A1, class _A2>
@@ -1630,6 +1693,9 @@
     return ::rintf(__x);
 #endif
 }
+
+using ::rint _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long double rint(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_rintl)
@@ -1661,6 +1727,9 @@
     return ::round(__x);
 #endif
 }
+
+using ::round _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long double round(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_roundl)
@@ -1685,6 +1754,7 @@
 // scalbln
 
 inline _LIBCPP_HIDE_FROM_ABI float       scalbln(float __x, long __y) _NOEXCEPT       {return ::scalblnf(__x, __y);}
+using ::scalbln _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double scalbln(long double __x, long __y) _NOEXCEPT {return ::scalblnl(__x, __y);}
 
 template <class _A1>
@@ -1695,6 +1765,7 @@
 // scalbn
 
 inline _LIBCPP_HIDE_FROM_ABI float       scalbn(float __x, int __y) _NOEXCEPT       {return ::scalbnf(__x, __y);}
+using ::scalbn _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double scalbn(long double __x, int __y) _NOEXCEPT {return ::scalbnl(__x, __y);}
 
 template <class _A1>
@@ -1705,6 +1776,7 @@
 // tgamma
 
 inline _LIBCPP_HIDE_FROM_ABI float       tgamma(float __x) _NOEXCEPT       {return ::tgammaf(__x);}
+using ::tgamma _LIBCPP_USING_IF_EXISTS;
 inline _LIBCPP_HIDE_FROM_ABI long double tgamma(long double __x) _NOEXCEPT {return ::tgammal(__x);}
 
 template <class _A1>
@@ -1722,6 +1794,9 @@
     return ::trunc(__x);
 #endif
 }
+
+using ::trunc _LIBCPP_USING_IF_EXISTS;
+
 inline _LIBCPP_HIDE_FROM_ABI long double trunc(long double __x) _NOEXCEPT
 {
 #if __has_builtin(__builtin_truncl)
@@ -1743,6 +1818,93 @@
 #endif
 }
 
+_LIBCPP_END_NAMESPACE_STD
+
+using std::signbit;
+using std::fpclassify;
+using std::isfinite;
+using std::isinf;
+using std::isnan;
+using std::isnormal;
+using std::isgreater;
+using std::isgreaterequal;
+using std::isless;
+using std::islessequal;
+using std::islessgreater;
+using std::isunordered;
+using std::isunordered;
+
+using std::acos;
+using std::asin;
+using std::atan;
+using std::atan2;
+using std::ceil;
+using std::cos;
+using std::cosh;
+
+using std::exp;
+
+using std::fabs;
+using std::floor;
+
+using std::fmod;
+
+using std::frexp;
+using std::ldexp;
+
+using std::log;
+
+using std::log10;
+using std::modf;
+
+using std::pow;
+
+using std::sin;
+using std::sinh;
+
+using std::sqrt;
+using std::tan;
+
+using std::tanh;
+
+using std::acosh;
+using std::asinh;
+using std::atanh;
+using std::cbrt;
+
+using std::copysign;
+
+using std::erf;
+using std::erfc;
+using std::exp2;
+using std::expm1;
+using std::fdim;
+using std::fma;
+using std::fmax;
+using std::fmin;
+using std::hypot;
+using std::ilogb;
+using std::lgamma;
+using std::llrint;
+using std::llround;
+using std::log1p;
+using std::log2;
+using std::logb;
+using std::lrint;
+using std::lround;
+
+using std::nearbyint;
+using std::nextafter;
+using std::nexttoward;
+using std::remainder;
+using std::remquo;
+using std::rint;
+using std::round;
+using std::scalbln;
+using std::scalbn;
+using std::tgamma;
+using std::trunc;
+
 } // extern "C++"
 
 #endif // __cplusplus