1 files changed, 24 insertions, 14 deletions

diff --git a/std/array_list.zig b/std/array_list.zig
index 65b7e023e2..04db4dd280 100644
--- a/std/array_list.zig
+++ b/std/array_list.zig
@@ -3,42 +3,46 @@ const assert = debug.assert;
 const mem = @import("mem.zig");
 const Allocator = mem.Allocator;
 
-pub fn ArrayList(comptime T: type) -> type{
-    struct {
+pub fn ArrayList(comptime T: type) -> type {
+    return AlignedArrayList(T, @alignOf(T));
+}
+
+pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
+    return struct {
         const Self = this;
 
         /// Use toSlice instead of slicing this directly, because if you don't
         /// specify the end position of the slice, this will potentially give
         /// you uninitialized memory.
-        items: []T,
+        items: []align(A) T,
         len: usize,
         allocator: &Allocator,
 
         /// Deinitialize with `deinit` or use `toOwnedSlice`.
         pub fn init(allocator: &Allocator) -> Self {
-            Self {
-                .items = []T{},
+            return Self {
+                .items = []align(A) T{},
                 .len = 0,
                 .allocator = allocator,
-            }
+            };
         }
 
         pub fn deinit(l: &Self) {
             l.allocator.free(l.items);
         }
 
-        pub fn toSlice(l: &Self) -> []T {
+        pub fn toSlice(l: &Self) -> []align(A) T {
             return l.items[0..l.len];
         }
 
-        pub fn toSliceConst(l: &const Self) -> []const T {
+        pub fn toSliceConst(l: &const Self) -> []align(A) const T {
             return l.items[0..l.len];
         }
 
         /// ArrayList takes ownership of the passed in slice. The slice must have been
         /// allocated with `allocator`.
         /// Deinitialize with `deinit` or use `toOwnedSlice`.
-        pub fn fromOwnedSlice(allocator: &Allocator, slice: []T) -> Self {
+        pub fn fromOwnedSlice(allocator: &Allocator, slice: []align(A) T) -> Self {
             return Self {
                 .items = slice,
                 .len = slice.len,
@@ -47,9 +51,9 @@ pub fn ArrayList(comptime T: type) -> type{
         }
 
         /// The caller owns the returned memory. ArrayList becomes empty.
-        pub fn toOwnedSlice(self: &Self) -> []T {
+        pub fn toOwnedSlice(self: &Self) -> []align(A) T {
             const allocator = self.allocator;
-            const result = allocator.shrink(T, self.items, self.len);
+            const result = allocator.alignedShrink(T, A, self.items, self.len);
             *self = init(allocator);
             return result;
         }
@@ -59,7 +63,7 @@ pub fn ArrayList(comptime T: type) -> type{
             *new_item_ptr = *item;
         }
 
-        pub fn appendSlice(l: &Self, items: []const T) -> %void {
+        pub fn appendSlice(l: &Self, items: []align(A) const T) -> %void {
             %return l.ensureCapacity(l.len + items.len);
             mem.copy(T, l.items[l.len..], items);
             l.len += items.len;
@@ -82,7 +86,7 @@ pub fn ArrayList(comptime T: type) -> type{
                 better_capacity += better_capacity / 2 + 8;
                 if (better_capacity >= new_capacity) break;
             }
-            l.items = %return l.allocator.realloc(T, l.items, better_capacity);
+            l.items = %return l.allocator.alignedRealloc(T, A, l.items, better_capacity);
         }
 
         pub fn addOne(l: &Self) -> %&T {
@@ -97,7 +101,13 @@ pub fn ArrayList(comptime T: type) -> type{
             self.len -= 1;
             return self.items[self.len];
         }
-    }
+
+        pub fn popOrNull(self: &Self) -> ?T {
+            if (self.len == 0)
+                return null;
+            return self.pop();
+        }
+    };
 }
 
 test "basic ArrayList test" {