[libcxx] Fix SFINAE in <cmath>. Patch from K-Ballo.
Delay instantiation of `__numeric_type` within <cmath>,
don't instantiate it when the `is_arithmetic` conditions do not hold as it causes
errors with user-defined types with ambiguous conversions. Fixes PR21083.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@219998 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/cmath b/include/cmath
index 4719aba..d3aa4be 100644
--- a/include/cmath
+++ b/include/cmath
@@ -727,11 +727,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
{
@@ -849,11 +849,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
fmod(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -952,11 +952,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
pow(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1114,11 +1114,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
copysign(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1192,11 +1192,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
fdim(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1216,12 +1216,12 @@
template <class _A1, class _A2, class _A3>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value &&
is_arithmetic<_A3>::value,
- typename __promote<_A1, _A2, _A3>::type
+ __promote<_A1, _A2, _A3>
>::type
fma(_A1 __lcpp_x, _A2 __lcpp_y, _A3 __lcpp_z) _NOEXCEPT
{
@@ -1242,11 +1242,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
fmax(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1266,11 +1266,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
fmin(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1290,11 +1290,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
hypot(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1459,11 +1459,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
nextafter(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1496,11 +1496,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
remainder(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
{
@@ -1520,11 +1520,11 @@
template <class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
+typename __lazy_enable_if
<
is_arithmetic<_A1>::value &&
is_arithmetic<_A2>::value,
- typename __promote<_A1, _A2>::type
+ __promote<_A1, _A2>
>::type
remquo(_A1 __lcpp_x, _A2 __lcpp_y, int* __lcpp_z) _NOEXCEPT
{