stlib arraylist

std/mem/mem.bro

@@ -34,6 +34,10 @@ _empty_slice func($T type, count usize) []mut T {
 	return pointer[..count]
 }
 
+empty func($T type) []mut T {
+	return _empty_slice(T, 0)
+}
+
 alloc func($T type, allocator Allocator, count usize) []mut T ! AllocError {
 	if count == 0 {
 		return _empty_slice(T, 0)
@@ -55,6 +59,43 @@ alloc func($T type, allocator Allocator, count usize) []mut T ! AllocError {
 	return .out_of_memory
 }
 
+realloc func($T type, allocator Allocator, memory []mut T, new_count usize) []mut T ! AllocError {
+	if new_count == memory.len {
+		return memory
+	}
+	if new_count == 0 {
+		free(T, allocator, memory)
+		return _empty_slice(T, 0)
+	}
+
+	element_size usize :: size_of(T)
+	if element_size == 0 {
+		return _empty_slice(T, new_count)
+	}
+	if new_count > max_value(usize) / element_size {
+		return .out_of_memory
+	}
+
+	old_memory ?*mut u8 = none
+	old_size usize = 0
+	if memory.len != 0 {
+		old_memory = ptr_cast(u8, memory.ptr)
+		old_size = memory.len * element_size
+	}
+	resized ?*mut u8 = raw_realloc(
+		allocator,
+		old_memory,
+		old_size,
+		new_count * element_size,
+		align_of(T),
+	)
+	if resized |bytes| {
+		pointer *mut T :: ptr_cast(T, bytes)
+		return pointer[..new_count]
+	}
+	return .out_of_memory
+}
+
 free func($T type, allocator Allocator, memory []mut T) void {
 	if memory.len != 0 and size_of(T) != 0 {
 		raw_free(allocator, ptr_cast(u8, memory.ptr), memory.len * size_of(T), align_of(T))