PR 574: use variadic template instead of initializer_list to implement fixed-size vector ctor from coefficients.

1 files changed, 22 insertions, 15 deletions

diff --git a/Eigen/src/Core/PlainObjectBase.h b/Eigen/src/Core/PlainObjectBase.h
index 04748e5e9..cd89fd365 100644
--- a/Eigen/src/Core/PlainObjectBase.h
+++ b/Eigen/src/Core/PlainObjectBase.h
@@ -527,15 +527,16 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
     }
 
     #ifdef EIGEN_PARSED_BY_DOXYGEN
-    /** \brief Construct a row of column vector with fixed size from an initializer list of coefficients. \cpp11
+    /** \brief Construct a row of column vector with fixed size from an arbitrary number of coefficients. \cpp11
       *
       * \only_for_vectors
       * 
-      * \warning To construct a column (resp. row) vector of fixed length, the number of values passed through
-      * the initializer list must match the the fixed number of rows (resp. columns) of \c *this.
+      * \warning To construct a column (resp. row) vector of fixed length, the number of values passed to this 
+      * constructor must match the the fixed number of rows (resp. columns) of \c *this.
       */
-    EIGEN_DEVICE_FUNC
-    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<Scalar>& list);
+    template <typename... ArgTypes>
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+    PlainObjectBase(const Scalar& a0, const Scalar& a1, const Scalar& a2,  const Scalar& a3, const ArgTypes&... args);
 
     /** \brief Constructs a Matrix or Array and initializes it by elements given by an initializer list of initializer
       * lists \cpp11
@@ -544,19 +545,25 @@ class PlainObjectBase : public internal::dense_xpr_base<Derived>::type
     explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<std::initializer_list<Scalar>>& list);
     #else // EIGEN_PARSED_BY_DOXYGEN
     #if EIGEN_HAS_CXX11
-    template<typename T>
-    EIGEN_DEVICE_FUNC
-    explicit EIGEN_STRONG_INLINE PlainObjectBase(const std::initializer_list<T>& list,
-      typename internal::enable_if<internal::is_same<T, Scalar>::value, T>::type* = 0,
-      typename internal::enable_if<RowsAtCompileTime != Dynamic
-                                   && ColsAtCompileTime != Dynamic
-                                   && IsVectorAtCompileTime ==  1, T>::type* = 0)
+  
+  protected:
+    enum { IsFixedSizeVectorAtCompileTime = RowsAtCompileTime != Dynamic && ColsAtCompileTime != Dynamic && IsVectorAtCompileTime == 1 };
+  public:
+    
+    template <typename... ArgTypes>
+    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
+    PlainObjectBase(const Scalar& a0, const Scalar& a1, const Scalar& a2,  const Scalar& a3, const ArgTypes&... args)
       : m_storage()
     {
       _check_template_params();
-      EIGEN_STATIC_ASSERT_FIXED_SIZE(PlainObjectBase);
-      resize(list.size());
-      std::copy(list.begin(), list.end(), m_storage.data());
+      EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(PlainObjectBase, sizeof...(args) + 4);
+      m_storage.data()[0] = a0;
+      m_storage.data()[1] = a1;
+      m_storage.data()[2] = a2;
+      m_storage.data()[3] = a3;
+      int i = 4;
+      auto x = {(m_storage.data()[i++] = args, 0)...};
+      static_cast<void>(x);
     }
 
     EIGEN_DEVICE_FUNC