Fix maybe uninitilized read warnings.

Fix initial allocation functions

include/boost/container/devector.hpp

@@ -224,7 +224,7 @@ class devector
    * **Complexity**: Constant.
    */
    devector(size_type n, reserve_only_tag_t, const allocator_type& allocator = allocator_type())
-      : m_(allocator, this->allocate(n), 0u, 0u, n)
+      : m_(allocator, 0u, 0u, n)
    {}
 
    /**
@@ -240,7 +240,7 @@ class devector
    * **Complexity**: Constant.
    */
    devector(size_type front_cap, size_type back_cap, reserve_only_tag_t, const allocator_type& allocator = allocator_type())
-      : m_(allocator, this->allocate(front_cap + back_cap), front_cap, front_cap, front_cap + back_cap)
+      : m_( allocator, front_cap, back_cap, front_cap + back_cap)
    {}
 
    /**
@@ -257,7 +257,7 @@ class devector
    * **Complexity**: Linear in `n`.
    */
    explicit devector(size_type n, const allocator_type& allocator = allocator_type())
-      : m_(allocator, n ? allocate(n): pointer(), 0u, n, n)
+      : m_(allocator, 0u, n, n)
    {
       // Cannot use construct_from_range/constant_iterator and copy_range,
       // because we are not allowed to default construct T
@@ -347,7 +347,7 @@ class devector
          BOOST_MOVE_I dtl::is_input_iterator<ForwardIterator>
          >::type * = 0)
       )
-      : m_(allocator, pointer(), 0u, 0u, 0u)
+      : m_(allocator)
    {
       const size_type n = boost::container::iterator_udistance(first, last);
       m_.buffer = n ? allocate(n) : pointer();
@@ -376,8 +376,7 @@ class devector
    * **Complexity**: Linear in the size of `x`.
    */
    devector(const devector& x)
-      : m_( allocator_traits_type::select_on_container_copy_construction(x.get_allocator_ref())
-          , pointer(), 0u, 0u, 0u)
+      : m_( allocator_traits_type::select_on_container_copy_construction(x.get_allocator_ref()))
    {
       const size_type n = x.size();
       m_.buffer = n ? allocate(n) : pointer();
@@ -467,7 +466,7 @@ class devector
    * **Equivalent to**: `devector(il.begin(), il.end())` or `devector(il.begin(), il.end(), allocator)`.
    */
    devector(const std::initializer_list<T>& il, const allocator_type& allocator = allocator_type())
-      : m_(allocator, pointer(), 0u, 0u, 0u)
+      : m_(allocator)
    {
       const size_type n = il.size();
       m_.buffer = n ? allocate(n) : pointer();
@@ -2059,15 +2058,11 @@ class devector
 
    pointer allocate(size_type capacity)
    {
-      //First detect overflow on smaller stored_size_types
-      if (capacity > stored_size_type(-1)){
-         boost::container::throw_length_error("get_next_capacity, allocator's max size reached");
-      }
-      //(clamp_by_stored_size_type<size_type>)(prefer_in_recvd_out_size, stored_size_type());
+      pointer const p = impl::do_allocate(get_allocator_ref(), capacity);
       #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
       ++m_.capacity_alloc_count;
       #endif // BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
-      return allocator_traits_type::allocate(get_allocator_ref(), capacity);
+      return p;
    }
 
    void destroy_elements(pointer begin, pointer end)
@@ -2082,7 +2077,7 @@ class devector
    {
       if (m_.buffer)
       {
-      allocator_traits_type::deallocate(get_allocator_ref(), m_.buffer, m_.capacity);
+         allocator_traits_type::deallocate(get_allocator_ref(), m_.buffer, m_.capacity);
       }
    }
 
@@ -2922,17 +2917,49 @@ class devector
 
    struct impl : allocator_type
    {
+      private:
+      impl(const impl &i);
+
+      public:
+      allocator_type &get_al()
+      {  return *this;  }
+
+      static pointer do_allocate(allocator_type &a, size_type cap)
+      {
+         if (cap) {
+            //First detect overflow on smaller stored_size_types
+            if (cap > stored_size_type(-1)){
+               boost::container::throw_length_error("get_next_capacity, allocator's max size reached");
+            }
+            return allocator_traits_type::allocate(a, cap);
+         }
+         else {
+            return pointer();
+         }
+      }
+
       impl()
          : allocator_type(), buffer(), front_idx(), back_idx(), capacity()
          #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
-         , capacity_alloc_count()
+         , capacity_alloc_count(0)
          #endif
       {}
 
       explicit impl(const allocator_type &a)
          : allocator_type(a), buffer(), front_idx(), back_idx(), capacity()
          #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
-         , capacity_alloc_count()
+         , capacity_alloc_count(0)
+         #endif
+      {}
+
+      impl(const allocator_type &a, size_type f, size_type b, size_type c)
+         : allocator_type(a), buffer(do_allocate(get_al(), c))
+         //static cast sizes, as the allocation function will take care of overflows
+         , front_idx(static_cast<stored_size_type>(f))
+         , back_idx(static_cast<stored_size_type>(b))
+         , capacity(static_cast<stored_size_type>(c))
+         #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
+         , capacity_alloc_count(size_type(buffer != pointer()))
          #endif
       {}
 
@@ -2943,7 +2970,7 @@ class devector
          , back_idx(static_cast<stored_size_type>(b))
          , capacity(static_cast<stored_size_type>(c))
          #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
-         , capacity_alloc_count()
+         , capacity_alloc_count(0)
          #endif
       {}
 
@@ -2954,7 +2981,7 @@ class devector
          , back_idx(static_cast<stored_size_type>(b))
          , capacity(static_cast<stored_size_type>(c))
          #ifdef BOOST_CONTAINER_DEVECTOR_ALLOC_STATS
-         , capacity_alloc_count()
+         , capacity_alloc_count(0)
          #endif
       {}