llvm/clang/include/clang/AST/CharUnits.h

//===--- CharUnits.h - Character units for sizes and offsets ----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
//  This file defines the CharUnits class
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_CHARUNITS_H
#define LLVM_CLANG_AST_CHARUNITS_H

#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/DataTypes.h"
#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
  /// 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.
  ///
  /// 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.
  ///
  /// 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 { … }; // class CharUnit
} // namespace clang

inline clang::CharUnits operator* (clang::CharUnits::QuantityType Scale,
                                   const clang::CharUnits &CU) { … }

namespace llvm {

template<> struct DenseMapInfo<clang::CharUnits> { … };

} // end namespace llvm

#endif // LLVM_CLANG_AST_CHARUNITS_H