[PATCH v3 8/8] include: Add math.h _(l|f)dtest function declarations.

[Rémi Bernon]

From: Rémi Bernon

And some C++ related inline helpers.
---
 include/msvcrt/math.h | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/include/msvcrt/math.h b/include/msvcrt/math.h
index 03c4bf57f59..5a41b061907 100644
--- a/include/msvcrt/math.h
+++ b/include/msvcrt/math.h
@@ -284,7 +284,22 @@ static const union {
 #define FP_ILOGB0 (-0x7fffffff - _C2)
 #define FP_ILOGBNAN 0x7fffffff

-#if _MSVCR_VER >= 120
+_ACRTIMP short __cdecl _dtest(double*);
+_ACRTIMP short __cdecl _ldtest(long double*);
+_ACRTIMP short __cdecl _fdtest(float*);
+
+#ifdef __cplusplus
+
+extern "C++" {
+inline int fpclassify(float x) throw() { return _fdtest(&x); }
+inline int fpclassify(double x) throw() { return _dtest(&x); }
+inline int fpclassify(long double x) throw() { return _ldtest(&x); }
+template <class T> inline bool isfinite(T x) throw() { return fpclassify(x) <= 0; }
+template <class T> inline bool isinf(T x) throw() { return fpclassify(x) == FP_INFINITE; }
+template <class T> inline bool isnan(T x) throw() { return fpclassify(x) == FP_NAN; }
+} /* extern "C++" */
+
+#elif _MSVCR_VER >= 120

_ACRTIMP short __cdecl _dclass(double);
 _ACRTIMP short __cdecl _fdclass(float);