Enable construction of vectors from std::initializer_list (#1836)

* Enable construction of vectors from `std::initializer_list`

testing/vector.cu

@@ -4,6 +4,9 @@
 #include <thrust/sequence.h>
 #include <thrust/device_malloc_allocator.h>
 
+#if THRUST_CPP_DIALECT >= 2011
+#include <initializer_list>
+#endif
 #include <vector>
 #include <list>
 #include <limits>
@@ -37,6 +40,30 @@ void TestVectorBool(void)
 }
 DECLARE_UNITTEST(TestVectorBool);
 
+template <class Vector>
+void TestVectorInitializerList(void)
+{
+    Vector v{1, 2, 3};
+    ASSERT_EQUAL(v.size(), 3lu);
+    ASSERT_EQUAL(v[0], 1);
+    ASSERT_EQUAL(v[1], 2);
+    ASSERT_EQUAL(v[2], 3);
+
+    v = {1, 2, 3, 4};
+    ASSERT_EQUAL(v.size(), 4lu);
+    ASSERT_EQUAL(v[0], 1);
+    ASSERT_EQUAL(v[1], 2);
+    ASSERT_EQUAL(v[2], 3);
+    ASSERT_EQUAL(v[3], 4);
+
+    const auto alloc = v.get_allocator();
+    Vector v2{{1, 2, 3}, alloc};
+    ASSERT_EQUAL(v2.size(), 3lu);
+    ASSERT_EQUAL(v2[0], 1);
+    ASSERT_EQUAL(v2[1], 2);
+    ASSERT_EQUAL(v2[2], 3);
+}
+DECLARE_VECTOR_UNITTEST(TestVectorInitializerList);
 
 template <class Vector>
 void TestVectorFrontBack(void)

thrust/detail/vector_base.h

@@ -28,6 +28,8 @@
 #include <thrust/detail/type_traits.h>
 #include <thrust/detail/config.h>
 #include <thrust/detail/contiguous_storage.h>
+
+#include <initializer_list>
 #include <vector>
 
 THRUST_NAMESPACE_BEGIN
@@ -123,12 +125,26 @@ template<typename T, typename Alloc>
      */
     vector_base &operator=(const vector_base &v);
 
-  #if THRUST_CPP_DIALECT >= 2011
     /*! Move assign operator moves from another vector_base.
      *  \param v The vector_base to move.
      */
     vector_base &operator=(vector_base &&v);
-  #endif
+
+    /*! This constructor builds a \p vector_base from an intializer_list.
+     *  \param il The intializer_list.
+     */
+    vector_base(std::initializer_list<T> il);
+
+    /*! This constructor builds a \p vector_base from an intializer_list.
+     *  \param il The intializer_list.
+     *  \param alloc The allocator to use by this device_vector.
+     */
+    vector_base(std::initializer_list<T> il, const Alloc &alloc);
+
+    /*! Assign operator copies from an initializer_list
+     *  \param il The initializer_list.
+     */
+    vector_base &operator=(std::initializer_list<T> il);
 
     /*! Copy constructor copies from an exemplar vector_base with different
      *  type.

thrust/detail/vector_base.inl

@@ -195,6 +195,34 @@ template<typename T, typename Alloc>
   return *this;
 } // end vector_base::operator=()
 
+  template<typename T, typename Alloc>
+    vector_base<T,Alloc>
+      ::vector_base(std::initializer_list<T> il)
+        :m_storage(),
+         m_size(0)
+  {
+    range_init(il.begin(), il.end());
+  } // end vector_base::vector_base()
+
+  template<typename T, typename Alloc>
+  vector_base<T,Alloc>
+    ::vector_base(std::initializer_list<T> il, const Alloc &alloc)
+    :m_storage(alloc),
+      m_size(0)
+  {
+    range_init(il.begin(), il.end());
+  } // end vector_base::vector_base()
+
+  template<typename T, typename Alloc>
+    vector_base<T,Alloc> &
+      vector_base<T,Alloc>
+      ::operator=(std::initializer_list<T> il)
+  {
+    assign(il.begin(), il.end());
+
+    return *this;
+  } // end vector_base::operator=()
+
 template<typename T, typename Alloc>
   template<typename IteratorOrIntegralType>
     void vector_base<T,Alloc>

thrust/device_vector.h

@@ -26,6 +26,7 @@
 #include <thrust/detail/vector_base.h>
 #include <thrust/device_allocator.h>
 
+#include <initializer_list>
 #include <vector>
 #include <utility>
 
@@ -197,6 +198,25 @@ template<typename T, typename Alloc = thrust::device_allocator<T> >
     device_vector &operator=(const detail::vector_base<OtherT,OtherAlloc> &v)
     { Parent::operator=(v); return *this; }
 
+    /*! This constructor builds a \p device_vector from an intializer_list.
+     *  \param il The intializer_list.
+     */
+    device_vector(std::initializer_list<T> il)
+      :Parent(il) {}
+
+    /*! This constructor builds a \p device_vector from an intializer_list.
+     *  \param il The intializer_list.
+     *  \param alloc The allocator to use by this device_vector.
+     */
+    device_vector(std::initializer_list<T> il, const Alloc &alloc)
+      :Parent(il, alloc) {}
+
+    /*! Assign an \p intializer_list with a matching element type
+     *  \param il The intializer_list.
+     */
+    device_vector &operator=(std::initializer_list<T> il)
+    { Parent::operator=(il); return *this; }
+
     /*! This constructor builds a \p device_vector from a range.
      *  \param first The beginning of the range.
      *  \param last The end of the range.

thrust/host_vector.h

@@ -25,6 +25,8 @@
 #include <thrust/detail/config.h>
 #include <thrust/detail/memory_wrapper.h>
 #include <thrust/detail/vector_base.h>
+
+#include <initializer_list>
 #include <vector>
 #include <utility>
 
@@ -216,6 +218,25 @@ template<typename T, typename Alloc = std::allocator<T> >
     __host__
     host_vector &operator=(const detail::vector_base<OtherT,OtherAlloc> &v)
     { Parent::operator=(v); return *this; }
+
+    /*! This constructor builds a \p host_vector from an intializer_list.
+     *  \param il The intializer_list.
+     */
+    host_vector(std::initializer_list<T> il)
+      :Parent(il) {}
+
+    /*! This constructor builds a \p host_vector from an intializer_list.
+     *  \param il The intializer_list.
+     *  \param alloc The allocator to use by this host_vector.
+     */
+    host_vector(std::initializer_list<T> il, const Alloc &alloc)
+      :Parent(il, alloc) {}
+
+    /*! Assign an \p intializer_list with a matching element type
+     *  \param il The intializer_list.
+     */
+    host_vector &operator=(std::initializer_list<T> il)
+    { Parent::operator=(il); return *this; }
 
     /*! This constructor builds a \p host_vector from a range.
      *  \param first The beginning of the range.

thrust/system/cpp/detail/vector.inl

@@ -98,6 +98,27 @@ template<typename T, typename Allocator>
     return *this;
   }
 #endif
+
+  template<typename T, typename Allocator>
+    vector<T,Allocator>
+      ::vector(std::initializer_list<T> il)
+        : super_t(il)
+  {}
+
+  template<typename T, typename Allocator>
+    vector<T,Allocator>
+      ::vector(std::initializer_list<T> il, const Allocator& alloc)
+        : super_t(il, alloc)
+  {}
+
+  template<typename T, typename Allocator>
+    vector<T,Allocator> &
+      vector<T,Allocator>
+        ::operator=(std::initializer_list<T> il)
+  {
+    super_t::operator=(il);
+    return *this;
+  }
 
 template<typename T, typename Allocator>
   template<typename OtherT, typename OtherAllocator>