[PATCH 1/1] include: Add signbit declarations for c++.

[Daniel Lehman]

From: Daniel Lehman

---
 include/msvcrt/math.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/msvcrt/math.h b/include/msvcrt/math.h
index 4f9840b3a02..8f1bd71ab72 100644
--- a/include/msvcrt/math.h
+++ b/include/msvcrt/math.h
@@ -287,6 +287,8 @@ static const union {
 _ACRTIMP short __cdecl _dtest(double*);
 _ACRTIMP short __cdecl _ldtest(long double*);
 _ACRTIMP short __cdecl _fdtest(float*);
+_ACRTIMP int   __cdecl _dsign(double);
+_ACRTIMP int   __cdecl _fdsign(float);

#ifdef __cplusplus

@@ -294,6 +296,8 @@ 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); }
+inline bool signbit(float x) throw() { return _fdsign(x) != 0; }
+inline bool signbit(double x) throw() { return _dsign(x) != 0; }
 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; }