From 0eb552a835500ed964836a8e0e3111843bff8aa1 Mon Sep 17 00:00:00 2001
From: Tobias Bucher <tobiasbucher5991@gmail.com>
Date: Thu, 23 Jul 2015 12:24:27 +0200
Subject: wtf8, char: Replace uses of `mem::transmute` with more specific
 functions

---
 src/libcore/char.rs | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

(limited to 'src/libcore')

diff --git a/src/libcore/char.rs b/src/libcore/char.rs
index 88aa805668c..84a0ed5ab3f 100644
--- a/src/libcore/char.rs
+++ b/src/libcore/char.rs
@@ -84,10 +84,17 @@ pub fn from_u32(i: u32) -> Option<char> {
     if (i > MAX as u32) || (i >= 0xD800 && i <= 0xDFFF) {
         None
     } else {
-        Some(unsafe { transmute(i) })
+        Some(unsafe { from_u32_unchecked(i) })
     }
 }
 
+/// Converts a `u32` to an `char`, not checking whether it is a valid unicode
+/// codepoint.
+#[inline]
+pub unsafe fn from_u32_unchecked(i: u32) -> char {
+    transmute(i)
+}
+
 /// Converts a number to the character representing it.
 ///
 /// # Return value
@@ -115,12 +122,11 @@ pub fn from_digit(num: u32, radix: u32) -> Option<char> {
         panic!("from_digit: radix is too high (maximum 36)");
     }
     if num < radix {
-        unsafe {
-            if num < 10 {
-                Some(transmute('0' as u32 + num))
-            } else {
-                Some(transmute('a' as u32 + num - 10))
-            }
+        let num = num as u8;
+        if num < 10 {
+            Some((b'0' + num) as char)
+        } else {
+            Some((b'a' + num - 10) as char)
         }
     } else {
         None
@@ -318,16 +324,13 @@ impl Iterator for EscapeUnicode {
                 Some('{')
             }
             EscapeUnicodeState::Value(offset) => {
-                let v = match ((self.c as i32) >> (offset * 4)) & 0xf {
-                    i @ 0 ... 9 => '0' as i32 + i,
-                    i => 'a' as i32 + (i - 10)
-                };
+                let c = from_digit(((self.c as u32) >> (offset * 4)) & 0xf, 16).unwrap();
                 if offset == 0 {
                     self.state = EscapeUnicodeState::RightBrace;
                 } else {
                     self.state = EscapeUnicodeState::Value(offset - 1);
                 }
-                Some(unsafe { transmute(v) })
+                Some(c)
             }
             EscapeUnicodeState::RightBrace => {
                 self.state = EscapeUnicodeState::Done;
-- 
cgit 1.4.1-3-g733a5


From c2fca7c95742cdd25198eae42d233d49db7026ea Mon Sep 17 00:00:00 2001
From: Tobias Bucher <tobiasbucher5991@gmail.com>
Date: Fri, 24 Jul 2015 00:45:21 +0200
Subject: Add unstable attribute to `char::from_u32_unchecked`

---
 src/libcore/char.rs | 1 +
 src/libstd/lib.rs   | 1 +
 2 files changed, 2 insertions(+)

(limited to 'src/libcore')

diff --git a/src/libcore/char.rs b/src/libcore/char.rs
index 84a0ed5ab3f..c6d0e97a0cd 100644
--- a/src/libcore/char.rs
+++ b/src/libcore/char.rs
@@ -91,6 +91,7 @@ pub fn from_u32(i: u32) -> Option<char> {
 /// Converts a `u32` to an `char`, not checking whether it is a valid unicode
 /// codepoint.
 #[inline]
+#[unstable(feature = "char_from_unchecked", reason = "recently added API")]
 pub unsafe fn from_u32_unchecked(i: u32) -> char {
     transmute(i)
 }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 82bc1314ad5..03e61247a83 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -209,6 +209,7 @@
 #![feature(borrow_state)]
 #![feature(box_raw)]
 #![feature(box_syntax)]
+#![feature(char_from_unchecked)]
 #![feature(char_internals)]
 #![feature(clone_from_slice)]
 #![feature(collections)]
-- 
cgit 1.4.1-3-g733a5