r181730 - Fix a wrong and confusing comment in CharUnits.h. Neither C nor C++ allows

[Richard Smith]

Author: rsmith
Date: Mon May 13 15:28:15 2013
New Revision: 181730

URL: http://llvm.org/viewvc/llvm-project?rev=181730&view=rev
Log:
Fix a wrong and confusing comment in CharUnits.h. Neither C nor C++ allows
bytes and character units to be different sizes.

Modified:
    cfe/trunk/include/clang/AST/CharUnits.h

Modified: cfe/trunk/include/clang/AST/CharUnits.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/CharUnits.h?rev=181730&r1=181729&r2=181730&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/CharUnits.h (original)
+++ cfe/trunk/include/clang/AST/CharUnits.h Mon May 13 15:28:15 2013
@@ -19,21 +19,20 @@
 #include "llvm/Support/MathExtras.h"
 
 namespace clang {
-  
+
   /// CharUnits - This is an opaque type for sizes expressed in character units.
-  /// Instances of this type represent a quantity as a multiple of the size 
+  /// Instances of this type represent a quantity as a multiple of the size
   /// of the standard C type, char, on the target architecture. As an opaque
   /// type, CharUnits protects you from accidentally combining operations on
-  /// quantities in bit units and character units. 
+  /// quantities in bit units and character units.
+  ///
+  /// In both C and C++, an object of type 'char', 'signed char', or 'unsigned
+  /// char' occupies exactly one byte, so 'character unit' and 'byte' refer to
+  /// the same quantity of storage. However, we use the term 'character unit'
+  /// rather than 'byte' to avoid an implication that a character unit is
+  /// exactly 8 bits.
   ///
-  /// It should be noted that characters and bytes are distinct concepts. Bytes
-  /// refer to addressable units of data storage on the target machine, and
-  /// characters are members of a set of elements used for the organization,
-  /// control, or representation of data. According to C99, bytes are allowed
-  /// to exceed characters in size, although currently, clang only supports
-  /// architectures where the two are the same size.
-  /// 
-  /// For portability, never assume that a target character is 8 bits wide. Use 
+  /// For portability, never assume that a target character is 8 bits wide. Use
   /// CharUnit values wherever you calculate sizes, offsets, or alignments
   /// in character units.
   class CharUnits {