| ... | ... | @@ -257,6 +257,24 @@ pub fn ArrayListAligned(comptime T: type, comptime alignment: ?u29) type { |
| 257 | 257 | return &self.items[self.items.len - 1]; |
| 258 | 258 | } |
| 259 | 259 | |
| 260 | /// Resize the array, adding `n` new elements, which have `undefined` values. |
| 261 | /// The return value is an array pointing to the newly allocated elements. |
| 262 | pub fn addManyAsArray(self: *Self, comptime n: usize) !*[n]T { |
| 263 | const prev_len = self.items.len; |
| 264 | try self.resize(self.items.len + n); |
| 265 | return self.items[prev_len..][0..n]; |
| 266 | } |
| 267 | |
| 268 | /// Resize the array, adding `n` new elements, which have `undefined` values. |
| 269 | /// The return value is an array pointing to the newly allocated elements. |
| 270 | /// Asserts that there is already space for the new item without allocating more. |
| 271 | pub fn addManyAsArrayAssumeCapacity(self: *Self, comptime n: usize) *[n]T { |
| 272 | assert(self.items.len + n <= self.capacity); |
| 273 | const prev_len = self.items.len; |
| 274 | self.items.len += n; |
| 275 | return self.items[prev_len..][0..n]; |
| 276 | } |
| 277 | |
| 260 | 278 | /// Remove and return the last element from the list. |
| 261 | 279 | /// Asserts the list has at least one item. |
| 262 | 280 | pub fn pop(self: *Self) T { |
| ... | ... | @@ -488,6 +506,24 @@ pub fn ArrayListAlignedUnmanaged(comptime T: type, comptime alignment: ?u29) typ |
| 488 | 506 | return &self.items[self.items.len - 1]; |
| 489 | 507 | } |
| 490 | 508 | |
| 509 | /// Resize the array, adding `n` new elements, which have `undefined` values. |
| 510 | /// The return value is an array pointing to the newly allocated elements. |
| 511 | pub fn addManyAsArray(self: *Self, allocator: *Allocator, comptime n: usize) !*[n]T { |
| 512 | const prev_len = self.items.len; |
| 513 | try self.resize(allocator, self.items.len + n); |
| 514 | return self.items[prev_len..][0..n]; |
| 515 | } |
| 516 | |
| 517 | /// Resize the array, adding `n` new elements, which have `undefined` values. |
| 518 | /// The return value is an array pointing to the newly allocated elements. |
| 519 | /// Asserts that there is already space for the new item without allocating more. |
| 520 | pub fn addManyAsArrayAssumeCapacity(self: *Self, comptime n: usize) *[n]T { |
| 521 | assert(self.items.len + n <= self.capacity); |
| 522 | const prev_len = self.items.len; |
| 523 | self.items.len += n; |
| 524 | return self.items[prev_len..][0..n]; |
| 525 | } |
| 526 | |
| 491 | 527 | /// Remove and return the last element from the list. |
| 492 | 528 | /// Asserts the list has at least one item. |
| 493 | 529 | /// This operation does not invalidate any element pointers. |
| ... | ... | @@ -727,3 +763,27 @@ test "std.ArrayList.writer" { |
| 727 | 763 | try writer.writeAll("efg"); |
| 728 | 764 | testing.expectEqualSlices(u8, list.items, "abcdefg"); |
| 729 | 765 | } |
| 766 | |
| 767 | test "addManyAsArray" { |
| 768 | const a = std.testing.allocator; |
| 769 | { |
| 770 | var list = ArrayList(u8).init(a); |
| 771 | defer list.deinit(); |
| 772 | |
| 773 | (try list.addManyAsArray(4)).* = "aoeu".*; |
| 774 | try list.ensureCapacity(8); |
| 775 | list.addManyAsArrayAssumeCapacity(4).* = "asdf".*; |
| 776 | |
| 777 | testing.expectEqualSlices(u8, list.items, "aoeuasdf"); |
| 778 | } |
| 779 | { |
| 780 | var list = ArrayListUnmanaged(u8){}; |
| 781 | defer list.deinit(a); |
| 782 | |
| 783 | (try list.addManyAsArray(a, 4)).* = "aoeu".*; |
| 784 | try list.ensureCapacity(a, 8); |
| 785 | list.addManyAsArrayAssumeCapacity(4).* = "asdf".*; |
| 786 | |
| 787 | testing.expectEqualSlices(u8, list.items, "aoeuasdf"); |
| 788 | } |
| 789 | } |
Andrew Kelley <andrew@ziglang.org> 2020-07-06 06:09:47+00:00