First version of a vector with uniqueness constraints (or a set with

deterministic, insertion-order iteration).

llvm-svn: 14702

include/Support/SetVector.h

@@ -0,0 +1,108 @@
+//===- SetVector.h - A set with insertion order iteration -------*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Reid Spencer and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file implements a set that has insertion order iteration 
+// characteristics. This is useful for keeping a set of things that need to be
+// visited later but in a deterministic order (insertion order). The interface
+// is purposefully minimal.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_SETVECTOR_H
+#define SUPPORT_SETVECTOR_H
+
+#include <set>
+#include <vector>
+
+namespace llvm {
+
+/// This class provides a way to keep a set of things that also has the 
+/// property of a deterministic iteration order. The order of iteration is the
+/// order of insertion.
+/// @breif A vector that has set insertion semantics.
+template <typename T>
+class SetVector {
+
+public:
+  typedef T value_type;
+  typedef T key_type;
+  typedef T& reference;
+  typedef const T& const_reference;
+  typedef std::set<value_type> set_type;
+  typedef std::vector<value_type> vector_type;
+  typedef typename vector_type::iterator iterator;
+  typedef typename vector_type::const_iterator const_iterator;
+  typedef typename vector_type::size_type size_type;
+
+  /// @brief Completely clear the SetVector
+  void clear() {
+    set_.clear();
+    vector_.clear();
+  }
+
+  /// @brief Determine if the SetVector is empty or not.
+  bool empty() const {
+    return vector_.empty();
+  }
+
+  /// @brief Determine the number of elements in the SetVector.
+  size_type size() const {
+    return vector_.size();
+  }
+
+  /// @brief Get an iterator to the beginning of the SetVector.
+  iterator begin() {
+    return vector_.begin();
+  }
+
+  /// @brief Get a const_iterator to the beginning of the SetVector.
+  const_iterator begin() const {
+    return vector_.begin();
+  }
+
+  /// @brief Get an iterator to the end of the SetVector.
+  iterator end() {
+    return vector_.end();
+  }
+
+  /// @brief Get a const_iterator to the end of the SetVector.
+  const_iterator end() const {
+    return vector_.end();
+  }
+
+  /// @brief Index into the SetVector.
+  const_reference operator[](size_type n) const {
+      return vector_[n];
+  }
+
+  /// @returns true iff the element was inserted into the SetVector.
+  /// @brief Insert a new element into the SetVector.
+  bool insert( const value_type& X ) {
+    std::pair<typename set_type::iterator,bool> insertion_result = set_.insert(X);
+    if ( insertion_result.second ) {
+      vector_.push_back(X);
+    }
+    return insertion_result.second;
+  }
+
+  /// @returns 0 if the element is not in the SetVector, 1 if it is.
+  /// @brief Count the number of elements of a given key in the SetVector.
+  size_type count( const key_type& key ) const {
+    return set_.count(key);
+  }
+
+private:
+  set_type set_;         ///< The set.
+  vector_type vector_;   ///< The vector.
+};
+
+} // End llvm namespace
+
+// vim: sw=2 ai
+#endif