include/llvm/ADT/StringSet.h

//===- StringSet.h - The LLVM Compiler Driver -------------------*- 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
//
//===----------------------------------------------------------------------===//
//
//  StringSet - A set-like wrapper for the StringMap.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ADT_STRINGSET_H
#define LLVM_ADT_STRINGSET_H

#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Allocator.h"
#include <cassert>
#include <initializer_list>
#include <utility>

namespace llvm {

  /// StringSet - A wrapper for StringMap that provides set-like functionality.
  template <class AllocatorTy = MallocAllocator>
  class StringSet : public StringMap<NoneType, AllocatorTy> {
    using base = StringMap<NoneType, AllocatorTy>;

  public:
    StringSet() = default;
    StringSet(std::initializer_list<StringRef> S) {
      for (StringRef X : S)
        insert(X);
    }
    explicit StringSet(AllocatorTy A) : base(A) {}

    std::pair<typename base::iterator, bool> insert(StringRef Key) {
      assert(!Key.empty());
      return base::insert(std::make_pair(Key, None));
    }

    template <typename InputIt>
    void insert(const InputIt &Begin, const InputIt &End) {
      for (auto It = Begin; It != End; ++It)
        base::insert(std::make_pair(*It, None));
    }

    template <typename ValueTy>
    std::pair<typename base::iterator, bool>
    insert(const StringMapEntry<ValueTy> &MapEntry) {
      return insert(MapEntry.getKey());
    }
  };

} // end namespace llvm

#endif // LLVM_ADT_STRINGSET_H