Add an example of free by borrow check

examples/borrow_check_free/Cargo.lock

@@ -0,0 +1,23 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "bdwgc-alloc"
+version = "0.2.0"
+dependencies = [
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "borrow_check_free"
+version = "0.1.0"
+dependencies = [
+ "bdwgc-alloc 0.2.0",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.51"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[metadata]
+"checksum libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)" = "bedcc7a809076656486ffe045abeeac163da1b558e963a31e29fbfbeba916917"

examples/borrow_check_free/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "borrow_check_free"
+version = "0.1.0"
+authors = ["Yota Toyama <raviqqe@gmail.com>"]
+edition = "2018"
+publish = false
+
+[dependencies]
+bdwgc-alloc = { path = "../.." }

examples/borrow_check_free/src/main.rs

@@ -0,0 +1,16 @@
+extern crate bdwgc_alloc;
+
+use bdwgc_alloc::Allocator;
+
+#[global_allocator]
+static GLOBAL_ALLOCATOR: Allocator = Allocator;
+
+fn main() {
+    unsafe { Allocator::initialize() }
+
+    let mut _n: Box<[u8; 2 ^ 8]> = Box::new([0; 2 ^ 8]);
+
+    loop {
+        _n = Box::new([0; 2 ^ 8]);
+    }
+}