rewrite uint::to_str_bytes to avoid raw pointers

src/libcore/uint-template.rs

@@ -179,7 +179,7 @@ pub pure fn to_str_bytes<U>(neg: bool, num: T, radix: uint,
  f: fn(v: &[u8]) -> U) -> U {
 
  #[inline(always)]
- fn digit(n: T) -> u8 {
+ pure fn digit(n: T) -> u8 {
  if n <= 9u as T {
  n as u8 + '0' as u8
  } else if n <= 15u as T {
@@ -195,35 +195,27 @@ pub pure fn to_str_bytes<U>(neg: bool, num: T, radix: uint,
  // Worst case: 64-bit number, binary-radix, with
  // a leading negative sign = 65 bytes.
  let buf : [mut u8 * 65] = [mut 0u8, ..65];
+ let len = buf.len();
 
- // FIXME (#2649): post-snapshot, you can do this without the raw
- // pointers and unsafe bits, and the codegen will prove it's all
- // in-bounds, no extra cost.
-
- unsafe {
- do vec::as_imm_buf(buf) |p, len| {
- let mp = p as *mut u8;
- let mut i = len;
- let mut n = num;
- let radix = radix as T;
- loop {
- i -= 1u;
- assert 0u < i && i < len;
- *ptr::mut_offset(mp, i) = digit(n % radix);
- n /= radix;
- if n == 0 as T { break; }
- }
-
- assert 0u < i && i < len;
-
- if neg {
- i -= 1u;
- *ptr::mut_offset(mp, i) = '-' as u8;
- }
-
- vec::raw::buf_as_slice(ptr::offset(p, i), len - i, f)
- }
+ let mut i = len;
+ let mut n = num;
+ let radix = radix as T;
+ loop {
+ i -= 1u;
+ assert 0u < i && i < len;
+ buf[i] = digit(n % radix);
+ n /= radix;
+ if n == 0 as T { break; }
+ }
+
+ assert 0u < i && i < len;
+
+ if neg {
+ i -= 1u;
+ buf[i] = '-' as u8;
  }
+
+ f(vec::view(buf, i, len))
 }
 
 /// Convert to a string