Merge branch 'main' into feature/tagged-pointer

This reverts commit a318362d25.

examples/Cargo.toml

@@ -5,4 +5,5 @@ members = [
   "free_by_borrow",
   "free_by_gc",
   "static_threads",
+  "tagged_pointer",
 ]

examples/tagged_pointer/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "tagged_pointer"
+version = "0.1.0"
+authors = ["Yota Toyama <raviqqe@gmail.com>"]
+edition = "2021"
+publish = false
+
+[dependencies]
+bdwgc-alloc = { path = "../.." }

examples/tagged_pointer/src/main.rs

@@ -0,0 +1,27 @@
+use bdwgc_alloc::Allocator;
+use std::alloc::{alloc, Layout};
+
+const BITS: usize = usize::MAX << 48 | 0x7;
+
+#[global_allocator]
+static GLOBAL_ALLOCATOR: Allocator = Allocator;
+
+fn main() {
+    unsafe { Allocator::initialize() }
+
+    loop {
+        let x = allocate();
+        unsafe { *x = 42 };
+        let x = x as usize | BITS;
+
+        assert_eq!(x & BITS, BITS);
+
+        Allocator::force_collect();
+
+        assert_eq!(unsafe { *((x & !BITS) as *mut usize) }, 42);
+    }
+}
+
+fn allocate() -> *mut usize {
+    (unsafe { alloc(Layout::from_size_align(1 << 8, 8).unwrap()) }) as *mut usize
+}