llvm/clang/include/clang/AST/ComparisonCategories.h

//===- ComparisonCategories.h - Three Way Comparison Data -------*- 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 Comparison Category enum and data types, which
//  store the types and expressions needed to support operator<=>
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_COMPARISONCATEGORIES_H
#define LLVM_CLANG_AST_COMPARISONCATEGORIES_H

#include "clang/Basic/LLVM.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/DenseMap.h"
#include <array>
#include <cassert>
#include <optional>
#include <vector>

namespace llvm {
  class StringRef;
  class APSInt;
}

namespace clang {

class ASTContext;
class VarDecl;
class CXXRecordDecl;
class Sema;
class QualType;
class NamespaceDecl;

/// An enumeration representing the different comparison categories
/// types.
///
/// C++20 [cmp.categories.pre] The types partial_ordering, weak_ordering, and
/// strong_ordering are collectively termed the comparison category types.
enum class ComparisonCategoryType : unsigned char { … };

/// Determine the common comparison type, as defined in C++2a
/// [class.spaceship]p4.
inline ComparisonCategoryType commonComparisonType(ComparisonCategoryType A,
                                                   ComparisonCategoryType B) { … }

/// Get the comparison category that should be used when comparing values of
/// type \c T.
std::optional<ComparisonCategoryType>
getComparisonCategoryForBuiltinCmp(QualType T);

/// An enumeration representing the possible results of a three-way
/// comparison. These values map onto instances of comparison category types
/// defined in the standard library. e.g. 'std::strong_ordering::less'.
enum class ComparisonCategoryResult : unsigned char { … };

class ComparisonCategoryInfo { … };

class ComparisonCategories { … };

} // namespace clang

#endif