1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef COUNTER_H 11 #define COUNTER_H 12 13 #include <functional> // for std::hash 14 15 struct Counter_base { static int gConstructed; }; 16 17 template <typename T> 18 class Counter : public Counter_base 19 { 20 public: 21 Counter() : data_() { ++gConstructed; } 22 Counter(const T &data) : data_(data) { ++gConstructed; } 23 Counter(const Counter& rhs) : data_(rhs.data_) { ++gConstructed; } 24 Counter& operator=(const Counter& rhs) { ++gConstructed; data_ = rhs.data_; return *this; } 25 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES 26 Counter(Counter&& rhs) : data_(std::move(rhs.data_)) { ++gConstructed; } 27 Counter& operator=(Counter&& rhs) { ++gConstructed; data_ = std::move(rhs.data_); return *this; } 28 #endif 29 ~Counter() { --gConstructed; } 30 31 const T& get() const {return data_;} 32 33 bool operator==(const Counter& x) const {return data_ == x.data_;} 34 bool operator< (const Counter& x) const {return data_ < x.data_;} 35 36 private: 37 T data_; 38 }; 39 40 int Counter_base::gConstructed = 0; 41 42 namespace std { 43 44 template <class T> 45 struct hash<Counter<T> > 46 : public std::unary_function<Counter<T>, std::size_t> 47 { 48 std::size_t operator()(const Counter<T>& x) const {return std::hash<T>(x.get());} 49 }; 50 } 51 52 #endif 53
