Add qfloat16::copySign() since we can't overload std::copysign()

Change-Id: Idfaf841b3eb3538f076ae4f0de2d7d029e1588fe
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/src/corelib/global/qfloat16.cpp b/src/corelib/global/qfloat16.cpp
index 6c21b7de5a..97709d7685 100644
--- a/src/corelib/global/qfloat16.cpp
+++ b/src/corelib/global/qfloat16.cpp
@@ -146,6 +146,14 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \since 5.15
+    \fn qfloat16::copySign(qfloat16 sign) const noexcept
+
+    Returns a qfloat16 with the sign of \a sign but the rest of its value taken
+    from this qfloat16. Serves as qfloat16's equivalent of std::copysign().
+*/
+
+/*!
     \internal
     \since 5.14
     Implements qFpClassify() for qfloat16.
diff --git a/src/corelib/global/qfloat16.h b/src/corelib/global/qfloat16.h
index 9a4f1800a4..c50fa36402 100644
--- a/src/corelib/global/qfloat16.h
+++ b/src/corelib/global/qfloat16.h
@@ -84,6 +84,9 @@ public:
     bool isNaN() const noexcept { return ((b16 >> 8) & 0x7e) == 0x7e; }
     bool isFinite() const noexcept { return ((b16 >> 8) & 0x7c) != 0x7c; }
     Q_CORE_EXPORT int fpClassify() const noexcept;
+    // Can't specialize std::copysign() for qfloat16
+    qfloat16 copySign(qfloat16 sign) const noexcept
+    { return qfloat16(Wrap((sign.b16 & 0x8000) | (b16 & 0x7fff))); }
     // Support for std::numeric_limits<qfloat16>
     static constexpr qfloat16 _limit_epsilon()    noexcept { return qfloat16(Wrap(0x1400)); }
     static constexpr qfloat16 _limit_min()        noexcept { return qfloat16(Wrap(0x400)); }