Added RFC on dereferencing *T

active/0000-dereferencing-pointers.md

@@ -0,0 +1,77 @@
+- Start Date: 2014-04-14
+- RFC PR #: (leave this empty)
+- Rust Issue #: (leave this empty)
+
+# Summary
+
+Make a way to dereference *T in a simpler way.
+
+# Motivation
+
+In most of the cases, embedded hardware is configured with memory-mapped registers. Often a peripheral would have a moderately big number of registers to the point where tracking each one by its address is hard and prone to errors.
+
+It's common to have structs mapping a given peripheral's ioregs in embedded C world. Unfortunately with rust using such structs require "junk code".
+
+# Detailed design
+
+Consider the following example:
+
+```rust
+// this struct maps over a number of ioregs
+pub struct UART {
+  REG_A:  u32,
+  REG_B:  u32,
+  _pad_0: u32,
+  REG_C:  u32,
+}
+
+impl UART {
+  // given the nature of regs, we must use volatile access
+  pub fn get_REG_A(&self) {
+    unsafe { volatile_load(&(self.REG_A)) }
+  }
+
+  pub fn set_REG_A(&self, val: u32) {
+    unsafe { volatile_store(&mut (self.REG_A), val) }
+  }
+  ...
+}
+
+// instantiate all peripherals over corresponding ioregs
+pub static UART0 : *mut UART = 0xdeadbeef as *mut UART;
+...
+```
+
+Rust requires an "unsafe" block and explicit dereferencing to access the registers:
+
+```rust
+let val: u32 = unsafe { (*UART0).REG_A() };
+```
+
+Instead of much simpler to read and understand syntax:
+
+```rust
+let val: u32 = UART0.REG_A();
+```
+
+# Alternatives
+
+It is possible to make a wrapping struct:
+
+```rust
+struct UARTWrapper {
+  uart: *mut UART,
+}
+
+// move all methods from UART to UARTWrapper
+
+static UART0Regs : *mut UART = 0xdeadbeef as *mut UART;
+pub static UART0 : UARTWrapper = UARTWrapper { uart: UART0Regs };
+```
+
+In this case, accessing methods on `UART0` is done with simple syntax, but the actual
+`static UART0` gets into output binary (as u32 0xdeadbeef), which requres developer to make a trade between syntax and binary size.
+
+# Unresolved questions
+
+How to actually simplify the syntax?