Patch by Kenneth Riddile: disable MSVC warnings, reenable them outside

of Eigen, and add a MSVC-friendly path in StaticAssert.

2 files changed, 15 insertions, 3 deletions

diff --git a/Eigen/src/Core/util/StaticAssert.h b/Eigen/src/Core/util/StaticAssert.h
index 0e2a70638..2594b73f8 100644
--- a/Eigen/src/Core/util/StaticAssert.h
+++ b/Eigen/src/Core/util/StaticAssert.h
@@ -74,8 +74,20 @@
       };
     };
 
-    #define EIGEN_STATIC_ASSERT(CONDITION,MSG) \
-      if (Eigen::ei_static_assert<CONDITION ? true : false>::MSG) {}
+    // Specialized implementation for MSVC to avoid "conditional
+    // expression is constant" warnings.  This implementation doesn't
+    // appear to work under GCC, hence the multiple implementations.
+    #ifdef _MSC_VER
+
+      #define EIGEN_STATIC_ASSERT(CONDITION,MSG) \
+        {Eigen::ei_static_assert<CONDITION ? true : false>::MSG;}
+
+    #else
+
+      #define EIGEN_STATIC_ASSERT(CONDITION,MSG) \
+        if (Eigen::ei_static_assert<CONDITION ? true : false>::MSG) {}
+
+    #endif
 
   #endif // not CXX0X
 
diff --git a/Eigen/src/Geometry/Quaternion.h b/Eigen/src/Geometry/Quaternion.h
index ec79afa25..f6630e63e 100644
--- a/Eigen/src/Geometry/Quaternion.h
+++ b/Eigen/src/Geometry/Quaternion.h
@@ -279,7 +279,7 @@ inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(const Quaternion& other
 template<typename Scalar>
 inline Quaternion<Scalar>& Quaternion<Scalar>::operator=(const AngleAxisType& aa)
 {
-  Scalar ha = 0.5*aa.angle();
+  Scalar ha = Scalar(0.5)*aa.angle(); // Scalar(0.5) to suppress precision loss warnings
   this->w() = ei_cos(ha);
   this->vec() = ei_sin(ha) * aa.axis();
   return *this;