add a std feature flag

For backwards compatibility this is not (yet) enabled by default.
Will be used for all API's that require functionality provided by the rust stdlib.

Author: cehteh

Cargo.toml

@@ -14,3 +14,4 @@ readme = "README.md"
 [features]
 default = ["atomic_append"]
 atomic_append = []
+std = []

README.md

@@ -3,3 +3,9 @@
 Allows one to store a header struct and a vector all inline in the same memory on the heap and share weak versions for minimizing random lookups in data structures
 
 If you use this without creating a weak ptr, it is safe. It is unsafe to create a weak pointer because you now have aliasing.
+
+## Features
+
+* `std`  
+  Enables API's that requires stdlib features. Provides more compatibility to `Vec`.
+  This feature is not enabled by default.

src/lib.rs

@@ -1,4 +1,4 @@
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 extern crate alloc;