cleanup part of code in deque for preparing insertion

Author: trcrsired

include/fast_io_dsal/impl/deque.h

@@ -564,11 +564,16 @@ inline constexpr void deque_rebalance_or_grow_2x_after_blocks_impl(dequecontrolt
 }
 
 template <typename allocator, typename dequecontroltype>
-inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes) noexcept
+inline constexpr void deque_allocate_on_empty_common_with_n_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes,
+																 ::std::size_t initial_allocated_block_counts) noexcept
 {
+	constexpr ::std::size_t maxval{::std::numeric_limits<::std::size_t>::max()};
+	if (initial_allocated_block_counts == maxval) [[unlikely]]
+	{
+		::fast_io::fast_terminate();
+	}
+	::std::size_t initial_allocated_block_counts_with_sentinel{initial_allocated_block_counts + 1u};
 	using block_typed_allocator = ::fast_io::typed_generic_allocator_adapter<allocator, typename dequecontroltype::controlreplacetype>;
-	constexpr ::std::size_t initial_allocated_block_counts{3};
-	constexpr ::std::size_t initial_allocated_block_counts_with_sentinel{initial_allocated_block_counts + 1u};
 	auto [allocated_blocks_ptr, allocated_blocks_count] = block_typed_allocator::allocate_at_least(initial_allocated_block_counts_with_sentinel);
 	// we need a null terminator as sentinel like c style string does
 	--allocated_blocks_count;
@@ -596,6 +601,13 @@ inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &cont
 	back_block.curr_ptr = halfposptr;
 }
 
+template <typename allocator, typename dequecontroltype>
+inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes) noexcept
+{
+	constexpr ::std::size_t initial_allocated_block_counts{3};
+	::fast_io::containers::details::deque_allocate_on_empty_common_with_n_impl<allocator>(controller, align, bytes, initial_allocated_block_counts);
+}
+
 template <typename allocator, typename dequecontroltype>
 inline constexpr void deque_grow_back_common_impl(
 	dequecontroltype &controller,
@@ -1193,6 +1205,28 @@ deque_erase_common_trivial_impl(::fast_io::containers::details::deque_controller
 	return first;
 }
 
+#if 0
+template <typename allocator, typename dequecontroltype>
+inline constexpr void deque_reserve_back_spaces_impl(dequecontroltype &controller, ::std::size_t n, ::std::size_t align, ::std::size_t blockbytes) noexcept
+{
+	::std::size_t const nb{n/blockbytes};
+
+	if (controller.controller_block.controller_start_ptr == nullptr)
+	{
+		::fast_io::containers::details::deque_allocate_on_empty_common_with_n_impl<allocator>(
+			controller, align, blockbytes, nb);
+		return;
+	}
+	
+}
+
+template <typename allocator, ::std::size_t align, ::std::size_t sz, ::std::size_t block_size, typename dequecontroltype>
+inline constexpr void deque_reserve_back_spaces(dequecontroltype &controller, ::std::size_t n)
+{
+
+}
+#endif
+
 } // namespace details
 
 template <::std::forward_iterator ForwardIt>