From bf1d83482b581e49499e545cc625155c1043ef0c Mon Sep 17 00:00:00 2001
From: pfg <pfg@pfg.pw>
Date: Wed, 2 Sep 2020 22:28:37 -0700
Subject: [PATCH 1/2] "Support" allocating 0 bit types

---
 lib/std/mem/Allocator.zig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/std/mem/Allocator.zig b/lib/std/mem/Allocator.zig
index bb59de2a7e70710ae10645d8cabeb4b5e1033612..f14373970a80cac639a6d21d25cbf1ac35f9c1ee 100644
--- a/lib/std/mem/Allocator.zig
+++ b/lib/std/mem/Allocator.zig
@@ -159,7 +159,7 @@ fn moveBytes(
 /// Returns a pointer to undefined memory.
 /// Call `destroy` with the result to free the memory.
 pub fn create(self: *Allocator, comptime T: type) Error!*T {
-    if (@sizeOf(T) == 0) return &(T{});
+    if (@sizeOf(T) == 0) return @as(*T, undefined);
     const slice = try self.allocAdvancedWithRetAddr(T, null, 1, .exact, @returnAddress());
     return &slice[0];
 }
-- 
2.54.0


From abe672956ed037077b23ac6aa29df3dd99795539 Mon Sep 17 00:00:00 2001
From: pfg <pfg@pfg.pw>
Date: Thu, 3 Sep 2020 16:33:47 -0700
Subject: [PATCH 2/2] Test 0 bit allocation

---
 lib/std/heap.zig | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/std/heap.zig b/lib/std/heap.zig
index d6977f2f9c3a4c0abe775fe6479f409955492784..492eb406568626304bb241db7381306b9819701b 100644
--- a/lib/std/heap.zig
+++ b/lib/std/heap.zig
@@ -915,6 +915,10 @@ pub fn testAllocator(base_allocator: *mem.Allocator) !void {
     testing.expect(slice.len == 10);
 
     allocator.free(slice);
+
+    const zero_bit_ptr = try allocator.create(u0);
+    zero_bit_ptr.* = 0;
+    allocator.destroy(zero_bit_ptr);
 }
 
 pub fn testAllocatorAligned(base_allocator: *mem.Allocator, comptime alignment: u29) !void {
-- 
2.54.0