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 #ifndef SUPPORT_TRACKED_VALUE_H 10 #define SUPPORT_TRACKED_VALUE_H 11 12 #include <cassert> 13 14 struct TrackedValue { 15 enum State { CONSTRUCTED, MOVED_FROM, DESTROYED }; 16 State state; 17 18 TrackedValue() : state(State::CONSTRUCTED) {} 19 20 TrackedValue(TrackedValue const& t) : state(State::CONSTRUCTED) { 21 assert(t.state != State::MOVED_FROM && "copying a moved-from object"); 22 assert(t.state != State::DESTROYED && "copying a destroyed object"); 23 } 24 25 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES 26 TrackedValue(TrackedValue&& t) : state(State::CONSTRUCTED) { 27 assert(t.state != State::MOVED_FROM && "double moving from an object"); 28 assert(t.state != State::DESTROYED && "moving from a destroyed object"); 29 t.state = State::MOVED_FROM; 30 } 31 #endif 32 33 TrackedValue& operator=(TrackedValue const& t) { 34 assert(state != State::DESTROYED && "copy assigning into destroyed object"); 35 assert(t.state != State::MOVED_FROM && "copying a moved-from object"); 36 assert(t.state != State::DESTROYED && "copying a destroyed object"); 37 state = t.state; 38 return *this; 39 } 40 41 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES 42 TrackedValue& operator=(TrackedValue&& t) { 43 assert(state != State::DESTROYED && "move assigning into destroyed object"); 44 assert(t.state != State::MOVED_FROM && "double moving from an object"); 45 assert(t.state != State::DESTROYED && "moving from a destroyed object"); 46 state = t.state; 47 t.state = State::MOVED_FROM; 48 return *this; 49 } 50 #endif 51 52 ~TrackedValue() { 53 assert(state != State::DESTROYED && "double-destroying an object"); 54 state = State::DESTROYED; 55 } 56 }; 57 58 #endif // SUPPORT_TRACKED_VALUE_H 59
