diff options
Diffstat (limited to 'include/clang/AST/CharUnits.h')
| -rw-r--r-- | include/clang/AST/CharUnits.h | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/include/clang/AST/CharUnits.h b/include/clang/AST/CharUnits.h index 082c672c21..09ff6828ef 100644 --- a/include/clang/AST/CharUnits.h +++ b/include/clang/AST/CharUnits.h @@ -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 { |