[2bb4a01] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // Node.hpp -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Wed May 8 10:27:04 2019 |
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[1e97287] | 11 | // Last Modified By : Andrew Beach |
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[dafe9e1] | 12 | // Last Modified On : Mon Jun 3 13:26:00 2019 |
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| 13 | // Update Count : 5 |
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[2bb4a01] | 14 | // |
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| 15 | |
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[cedb545] | 16 | #pragma once |
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| 17 | |
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[2bb4a01] | 18 | #include <cassert> |
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| 19 | #include <iosfwd> |
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[b7d92b96] | 20 | #include <type_traits> // for remove_reference |
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[cedb545] | 21 | |
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[1346914] | 22 | #include "Common/ErrorObjects.h" // for SemanticErrorException |
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| 23 | |
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[cedb545] | 24 | namespace ast { |
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[2bb4a01] | 25 | |
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| 26 | class Visitor; |
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| 27 | |
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| 28 | /// Base class for all AST nodes. |
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| 29 | /// Keeps both strong and weak reference counts. |
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[f47f887] | 30 | class Node { |
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| 31 | public: |
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[14cebb7a] | 32 | // override defaults to ensure assignment doesn't |
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[2bb4a01] | 33 | // change/share reference counts |
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| 34 | Node() = default; |
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[6d51bd7] | 35 | Node(const Node&) : strong_count(0), weak_count(0) {} |
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| 36 | Node(Node&&) : strong_count(0), weak_count(0) {} |
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[2bb4a01] | 37 | Node& operator= (const Node&) = delete; |
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| 38 | Node& operator= (Node&&) = delete; |
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[f47f887] | 39 | virtual ~Node() = default; |
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[cedb545] | 40 | |
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[6d51bd7] | 41 | virtual const Node * accept( Visitor & v ) const = 0; |
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[2bb4a01] | 42 | |
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| 43 | /// Types of node references |
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[f47f887] | 44 | enum class ref_type { |
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| 45 | strong, |
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| 46 | weak |
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| 47 | }; |
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[cedb545] | 48 | |
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[4864a73] | 49 | bool unique() const { return strong_count == 1; } |
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| 50 | |
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[87701b6] | 51 | private: |
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| 52 | /// Make a copy of this node; should be overridden in subclass with more precise return type |
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| 53 | virtual Node * clone() const = 0; |
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| 54 | |
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| 55 | /// Must be copied in ALL derived classes |
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| 56 | template<typename node_t> |
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| 57 | friend node_t * mutate(const node_t * node); |
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| 58 | |
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| 59 | mutable size_t strong_count = 0; |
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| 60 | mutable size_t weak_count = 0; |
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[4864a73] | 61 | mutable bool was_ever_strong = false; |
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[87701b6] | 62 | |
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| 63 | void increment(ref_type ref) const { |
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[f47f887] | 64 | switch (ref) { |
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[4864a73] | 65 | case ref_type::strong: strong_count++; was_ever_strong = true; break; |
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[6d51bd7] | 66 | case ref_type::weak : weak_count ++; break; |
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[cedb545] | 67 | } |
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[f47f887] | 68 | } |
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[cedb545] | 69 | |
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[87701b6] | 70 | void decrement(ast::Node::ref_type ref) const { |
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[f47f887] | 71 | switch (ref) { |
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[6d51bd7] | 72 | case ref_type::strong: strong_count--; break; |
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| 73 | case ref_type::weak : weak_count --; break; |
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[cedb545] | 74 | } |
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| 75 | |
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[6d51bd7] | 76 | if(!strong_count && !weak_count) { |
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[f47f887] | 77 | delete this; |
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[6a625de] | 78 | } |
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[f47f887] | 79 | } |
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[6a625de] | 80 | |
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[87701b6] | 81 | template< typename node_t, enum Node::ref_type ref_t > |
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| 82 | friend class ptr_base; |
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[f47f887] | 83 | }; |
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| 84 | |
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[b7d92b96] | 85 | /// Mutate a node, non-member function to avoid static type |
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| 86 | /// problems and be able to use auto return |
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[f47f887] | 87 | template<typename node_t> |
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[87701b6] | 88 | node_t * mutate( const node_t * node ) { |
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| 89 | if (node->strong_count <= 1) { |
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[f47f887] | 90 | return const_cast<node_t *>(node); |
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[6a625de] | 91 | } |
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| 92 | |
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[f47f887] | 93 | assertf( |
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| 94 | node->weak_count == 0, |
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| 95 | "Error: mutating node with weak references to it will invalided some references" |
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| 96 | ); |
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| 97 | return node->clone(); |
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| 98 | } |
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| 99 | |
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[b7d92b96] | 100 | /// Mutate a node field (only clones if not equal to existing value) |
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[2d11663] | 101 | template<typename node_t, typename field_t, typename assn_t> |
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| 102 | const node_t * mutate_field( const node_t * node, field_t node_t::* field, assn_t && val ) { |
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| 103 | // skip mutate if equivalent |
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[b7d92b96] | 104 | if ( node->*field == val ) return node; |
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| 105 | |
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[2d11663] | 106 | // mutate and return |
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| 107 | node_t * ret = mutate( node ); |
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| 108 | ret->*field = std::forward< assn_t >( val ); |
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| 109 | return ret; |
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| 110 | } |
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| 111 | |
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| 112 | /// Mutate a single index of a node field (only clones if not equal to existing value) |
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| 113 | template<typename node_t, typename coll_t, typename ind_t, typename field_t> |
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| 114 | const node_t * mutate_field_index( |
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| 115 | const node_t * node, coll_t node_t::* field, ind_t i, field_t && val |
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| 116 | ) { |
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| 117 | // skip mutate if equivalent |
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| 118 | if ( (node->*field)[i] == val ) return node; |
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| 119 | |
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| 120 | // mutate and return |
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[b7d92b96] | 121 | node_t * ret = mutate( node ); |
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[2d11663] | 122 | (ret->*field)[i] = std::forward< field_t >( val ); |
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[b7d92b96] | 123 | return ret; |
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| 124 | } |
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| 125 | |
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[54e41b3] | 126 | std::ostream& operator<< ( std::ostream& out, const Node * node ); |
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[2bb4a01] | 127 | |
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[d8938622] | 128 | /// Call a visitor on a possibly-null node |
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| 129 | template<typename node_t> |
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| 130 | auto maybe_accept( const node_t * n, Visitor & v ) -> decltype( n->accept(v) ) { |
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| 131 | return n ? n->accept( v ) : nullptr; |
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| 132 | } |
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| 133 | |
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[1346914] | 134 | /// Call a visitor on a collection of nodes, throwing any exceptions when completed |
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| 135 | template< typename Container > |
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| 136 | void accept_each( const Container & c, Visitor & v ) { |
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| 137 | SemanticErrorException errors; |
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| 138 | for ( const auto & i : c ) { |
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| 139 | try { |
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| 140 | if ( i ) { |
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| 141 | i->accept( v ); |
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| 142 | } |
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| 143 | } catch ( SemanticErrorException & e ) { |
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| 144 | errors.append( e ); |
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| 145 | } |
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| 146 | } |
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| 147 | if ( ! errors.isEmpty() ) { |
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| 148 | throw errors; |
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| 149 | } |
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| 150 | } |
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| 151 | |
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[9e1d485] | 152 | /// Base class for the smart pointer types |
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| 153 | /// should never really be used. |
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| 154 | template< typename node_t, enum Node::ref_type ref_t > |
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[f47f887] | 155 | class ptr_base { |
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| 156 | public: |
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| 157 | ptr_base() : node(nullptr) {} |
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[87701b6] | 158 | ptr_base( const node_t * n ) : node(n) { if( node ) _inc(node); } |
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[dafe9e1] | 159 | ~ptr_base() { if( node ) { auto tmp = node; node = nullptr; _dec(tmp); } } |
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[f47f887] | 160 | |
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[f685679] | 161 | ptr_base( const ptr_base & o ) : node(o.node) { |
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| 162 | if( node ) _inc(node); |
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| 163 | } |
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| 164 | |
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[d76c588] | 165 | ptr_base( ptr_base && o ) : node(o.node) { o.node = nullptr; } |
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[f685679] | 166 | |
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[9e1d485] | 167 | template< enum Node::ref_type o_ref_t > |
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[60aaa51d] | 168 | ptr_base( const ptr_base<node_t, o_ref_t> & o ) : node(o.get()) { |
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[87701b6] | 169 | if( node ) _inc(node); |
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[6a625de] | 170 | } |
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| 171 | |
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[9e1d485] | 172 | template< enum Node::ref_type o_ref_t > |
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[60aaa51d] | 173 | ptr_base( ptr_base<node_t, o_ref_t> && o ) : node(o.get()) { |
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[87701b6] | 174 | if( node ) _inc(node); |
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[6d51bd7] | 175 | } |
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| 176 | |
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| 177 | template<typename o_node_t> |
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| 178 | ptr_base & operator=( const o_node_t * node ) { |
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[dafe9e1] | 179 | assign( strict_dynamic_cast<const node_t *, nullptr>(node) ); |
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[6d51bd7] | 180 | return *this; |
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[f47f887] | 181 | } |
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[cedb545] | 182 | |
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[f685679] | 183 | ptr_base & operator=( const ptr_base & o ) { |
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| 184 | assign(o.node); |
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| 185 | return *this; |
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| 186 | } |
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| 187 | |
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| 188 | ptr_base & operator=( ptr_base && o ) { |
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[d76c588] | 189 | if ( node == o.node ) return *this; |
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| 190 | if ( node ) _dec(node); |
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| 191 | node = o.node; |
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| 192 | o.node = nullptr; |
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[f685679] | 193 | return *this; |
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| 194 | } |
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| 195 | |
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[9e1d485] | 196 | template< enum Node::ref_type o_ref_t > |
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[f47f887] | 197 | ptr_base & operator=( const ptr_base<node_t, o_ref_t> & o ) { |
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[60aaa51d] | 198 | assign(o.get()); |
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[f47f887] | 199 | return *this; |
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| 200 | } |
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[cedb545] | 201 | |
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[9e1d485] | 202 | template< enum Node::ref_type o_ref_t > |
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[f47f887] | 203 | ptr_base & operator=( ptr_base<node_t, o_ref_t> && o ) { |
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[60aaa51d] | 204 | assign(o.get()); |
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[f47f887] | 205 | return *this; |
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| 206 | } |
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[cedb545] | 207 | |
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[4864a73] | 208 | const node_t * get() const { _check(); return node; } |
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| 209 | const node_t * operator->() const { _check(); return node; } |
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| 210 | const node_t & operator* () const { _check(); return *node; } |
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| 211 | explicit operator bool() const { _check(); return node; } |
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| 212 | operator const node_t * () const { _check(); return node; } |
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[cedb545] | 213 | |
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[54e41b3] | 214 | /// wrapper for convenient access to dynamic_cast |
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[fdbd4fd] | 215 | template<typename o_node_t> |
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[4864a73] | 216 | const o_node_t * as() const { _check(); return dynamic_cast<const o_node_t *>(node); } |
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[fdbd4fd] | 217 | |
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[ee574a2] | 218 | /// wrapper for convenient access to strict_dynamic_cast |
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| 219 | template<typename o_node_t> |
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[546e712] | 220 | const o_node_t * strict_as() const { _check(); return strict_dynamic_cast<const o_node_t *>(node); } |
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[ee574a2] | 221 | |
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[76ed81f] | 222 | /// Returns a mutable version of the pointer in this node. |
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| 223 | node_t * get_and_mutate(); |
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| 224 | |
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[54e41b3] | 225 | /// Sets this pointer to a mutated version of a pointer (possibly) owned elsehere. |
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| 226 | /// Returns a mutable version of the pointer in this node. |
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[10a1225] | 227 | node_t * set_and_mutate( const node_t * n ); |
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[54e41b3] | 228 | |
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[f47f887] | 229 | using ptr = const node_t *; |
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[cedb545] | 230 | |
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[f47f887] | 231 | private: |
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[9e1d485] | 232 | void assign( const node_t * other ) { |
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[87701b6] | 233 | if( other ) _inc(other); |
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| 234 | if( node ) _dec(node ); |
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[f47f887] | 235 | node = other; |
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| 236 | } |
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[cedb545] | 237 | |
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[87701b6] | 238 | void _inc( const node_t * other ); |
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| 239 | void _dec( const node_t * other ); |
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[4864a73] | 240 | void _check() const; |
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[87701b6] | 241 | |
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[9e1d485] | 242 | const node_t * node; |
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[f47f887] | 243 | }; |
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[cedb545] | 244 | |
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[2bb4a01] | 245 | /// Owning pointer to node |
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[f47f887] | 246 | template< typename node_t > |
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| 247 | using ptr = ptr_base< node_t, Node::ref_type::strong >; |
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[cedb545] | 248 | |
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[2bb4a01] | 249 | /// Observing pointer to node |
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[f47f887] | 250 | template< typename node_t > |
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| 251 | using readonly = ptr_base< node_t, Node::ref_type::weak >; |
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[2bb4a01] | 252 | } |
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| 253 | |
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| 254 | // Local Variables: // |
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| 255 | // tab-width: 4 // |
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| 256 | // mode: c++ // |
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| 257 | // compile-command: "make install" // |
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[1e97287] | 258 | // End: // |
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