| 1 | //-----------------------------------------------------------------------------
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| 2 | // Part of reboost (http://reboost.org). Released under the
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| 3 | // BSD 2-clause license (http://www.opensource.org/licenses/bsd-license.php).
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| 4 | // Copyright 2012, Sebastian Mies <mies@reboost.org> --- All rights reserved.
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| 5 | //-----------------------------------------------------------------------------
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| 6 |
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| 7 | #ifndef BUFFER_HPP_
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| 8 | #define BUFFER_HPP_
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| 9 |
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| 10 | #include<cassert>
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| 11 | #include<iostream>
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| 12 |
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| 13 | namespace reboost {
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| 14 |
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| 15 | /// buffer size and octet
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| 16 | typedef size_t bsize_t;
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| 17 | typedef unsigned char boctet_t;
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| 18 |
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| 19 | /**
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| 20 | * A simple buffer.
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| 21 | *
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| 22 | * @author Sebastian Mies <mies@cpptools.org>
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| 23 | */
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| 24 | class buffer_t {
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| 25 | typedef buffer_t self;
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| 26 | protected:
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| 27 | bsize_t size_;
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| 28 | boctet_t * data_;
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| 29 |
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| 30 | public:
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| 31 | /// a buffer of zero size, pointing to NULL
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| 32 | inline buffer_t() :
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| 33 | size_(0), data_((boctet_t*) 0) {
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| 34 | }
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| 35 |
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| 36 | /// copy constructor
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| 37 | inline buffer_t(const self& rhs) :
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| 38 | size_(rhs.size_), data_(rhs.data_){
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| 39 | }
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| 40 |
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| 41 | /// allocate a buffer of a certain size
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| 42 | inline buffer_t(bsize_t size) :
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| 43 | size_(size), data_(new boctet_t[size]) {
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| 44 | }
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| 45 |
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| 46 | /// convenience constructor
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| 47 | inline buffer_t(bsize_t size, boctet_t* data) :
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| 48 | size_(size), data_(data) {
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| 49 | }
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| 50 |
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| 51 | /// interpret string as buffer (maximal size 64K)
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| 52 | inline explicit buffer_t(const char* string) :
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| 53 | size_(0), data_((boctet_t*) string) {
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| 54 | while (string[size_] != 0 && size_ < 64000)
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| 55 | size_++;
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| 56 | }
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| 57 |
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| 58 | /// clone a buffer
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| 59 | inline self clone() const {
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| 60 | buffer_t n(this->size_);
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| 61 | for (bsize_t i = 0; i < size_; i++)
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| 62 | n.data_[i] = this->data_[i];
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| 63 | return n;
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| 64 | }
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| 65 |
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| 66 | /// copy a buffer pointer and size.
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| 67 | inline self& operator=(const self& rhs) {
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| 68 | this->size_ = rhs.size_;
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| 69 | this->data_ = rhs.data_;
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| 70 | return *this;
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| 71 | }
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| 72 |
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| 73 | /// return sub-buffer.
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| 74 | inline self operator()(bsize_t index, bsize_t size = 0) const {
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| 75 | self n(*this);
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| 76 | n.data_ += index;
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| 77 | if (size == 0) n.size_ -= index;
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| 78 | else n.size_ = size;
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| 79 | return n;
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| 80 | }
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| 81 |
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| 82 | /// returns a data element at given index
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| 83 | inline boctet_t operator[](bsize_t index) const {
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| 84 | return data_[index];
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| 85 | }
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| 86 |
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| 87 | /// returns a data element at given index
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| 88 | inline boctet_t& operator[](bsize_t index) {
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| 89 | return data_[index];
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| 90 | }
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| 91 |
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| 92 | /// assigns contents to another buffer
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| 93 | inline const self& copy_to( self& buf, bsize_t index = 0 ) const {
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| 94 | assert(index + size_ <= buf.size_);
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| 95 | const boctet_t *src=data_;
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| 96 | boctet_t* dst=buf.data_+index;
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| 97 | for (bsize_t i=0; i<size_; i++, src++, dst++ ) *dst = *src;
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| 98 | return *this;
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| 99 | }
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| 100 |
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| 101 | /// convert to pointer of an immutable type
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| 102 | template<class T> inline const T* cast_to() {
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| 103 | return (T*)data_;
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| 104 | }
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| 105 |
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| 106 | /// set buffer size
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| 107 | inline void size( bsize_t size ) {
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| 108 | size_ = size;
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| 109 | }
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| 110 |
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| 111 |
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| 112 | /// returns the size in octets
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| 113 | inline bsize_t size() const {
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| 114 | return size_;
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| 115 | }
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| 116 |
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| 117 | /// sets the data pointer
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| 118 | inline void data( boctet_t* data ) {
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| 119 | data_ = data;
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| 120 | }
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| 121 |
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| 122 | /// returns a pointer to immutable data
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| 123 | inline const boctet_t * data() const {
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| 124 | return data_;
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| 125 | }
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| 126 |
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| 127 | /// returns a pointer to mutable data
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| 128 | inline boctet_t * mutable_data() {
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| 129 | return data_;
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| 130 | }
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| 131 |
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| 132 | /// returns a hash value of this buffer using the ELF hash
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| 133 | inline size_t hash() const {
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| 134 | unsigned h = 0, g;
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| 135 | for (size_t i = 0; i < size_; i++) {
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| 136 | h = (h << 4) + data_[i];
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| 137 | g = h & 0xf0000000L;
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| 138 | if (g != 0) h ^= g >> 24;
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| 139 | h &= ~g;
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| 140 | }
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| 141 | return (size_t) h;
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| 142 | }
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| 143 |
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| 144 | /// returns true if data_ is null
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| 145 | inline bool is_null() const {
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| 146 | return data_ == NULL;
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| 147 | }
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| 148 |
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| 149 | /// returns true if size is zero
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| 150 | inline bool is_empty() const {
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| 151 | return size_ == 0;
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| 152 | }
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| 153 |
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| 154 | /// compare two buffers
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| 155 | inline int compare_to(const self& rhs) const {
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| 156 | if (rhs.data_ == data_ && rhs.size_ == size_) return 0;
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| 157 | if (size_ < rhs.size_) return -1;
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| 158 | if (size_ > rhs.size_) return 1;
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| 159 | for (bsize_t i = 0; i < size_; i++) {
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| 160 | if (data_[i] > rhs.data_[i]) return 1;
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| 161 | if (data_[i] < rhs.data_[i]) return -1;
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| 162 | }
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| 163 | return 0;
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| 164 | }
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| 165 |
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| 166 | /// convenience
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| 167 | inline bool operator==(const self& rhs) const {
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| 168 | return (compare_to(rhs) == 0);
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| 169 | }
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| 170 | inline bool operator!=(const self& rhs) const {
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| 171 | return (compare_to(rhs) != 0);
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| 172 | }
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| 173 | inline bool operator<(const self& rhs) const {
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| 174 | return (compare_to(rhs) < 0);
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| 175 | }
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| 176 | inline bool operator<=(const self& rhs) const {
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| 177 | return (compare_to(rhs) <= 0);
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| 178 | }
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| 179 | inline bool operator>(const self& rhs) const {
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| 180 | return (compare_to(rhs) > 0);
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| 181 | }
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| 182 | inline bool operator>=(const self& rhs) const {
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| 183 | return (compare_to(rhs) >= 0);
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| 184 | }
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| 185 | };
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| 186 |
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| 187 | /// stream operator
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| 188 | std::ostream& operator<<( std::ostream& os, const buffer_t& buf );
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| 189 |
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| 190 | }
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| 191 |
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| 192 | /// boost hash
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| 193 | namespace boost {
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| 194 | inline size_t hash_value(const reboost::buffer_t& buf) {
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| 195 | return buf.hash();
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| 196 | }}
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| 197 |
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| 198 | #endif /* BUFFER_HPP_ */
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