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authorKenneth Heafield <github@kheafield.com>2013-01-22 21:37:49 +0000
committerKenneth Heafield <github@kheafield.com>2013-01-22 21:37:49 +0000
commitb35a7f3a96ff8ae42e15922dd6949bf9f5d15501 (patch)
tree26edbe78931ffc50864a899c087d851005fe560b /klm/util/string_piece_hash.hh
parent51a412aa7f5f50035cf28a274a70508c839f3d40 (diff)
KenLM 58da338b
Diffstat (limited to 'klm/util/string_piece_hash.hh')
-rw-r--r--klm/util/string_piece_hash.hh43
1 files changed, 43 insertions, 0 deletions
diff --git a/klm/util/string_piece_hash.hh b/klm/util/string_piece_hash.hh
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+++ b/klm/util/string_piece_hash.hh
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+#ifndef UTIL_STRING_PIECE_HASH__
+#define UTIL_STRING_PIECE_HASH__
+
+#include "util/string_piece.hh"
+
+#include <boost/functional/hash.hpp>
+#include <boost/version.hpp>
+
+inline size_t hash_value(const StringPiece &str) {
+ return boost::hash_range(str.data(), str.data() + str.length());
+}
+
+/* Support for lookup of StringPiece in boost::unordered_map<std::string> */
+struct StringPieceCompatibleHash : public std::unary_function<const StringPiece &, size_t> {
+ size_t operator()(const StringPiece &str) const {
+ return hash_value(str);
+ }
+};
+
+struct StringPieceCompatibleEquals : public std::binary_function<const StringPiece &, const std::string &, bool> {
+ bool operator()(const StringPiece &first, const StringPiece &second) const {
+ return first == second;
+ }
+};
+template <class T> typename T::const_iterator FindStringPiece(const T &t, const StringPiece &key) {
+#if BOOST_VERSION < 104200
+ std::string temp(key.data(), key.size());
+ return t.find(temp);
+#else
+ return t.find(key, StringPieceCompatibleHash(), StringPieceCompatibleEquals());
+#endif
+}
+
+template <class T> typename T::iterator FindStringPiece(T &t, const StringPiece &key) {
+#if BOOST_VERSION < 104200
+ std::string temp(key.data(), key.size());
+ return t.find(temp);
+#else
+ return t.find(key, StringPieceCompatibleHash(), StringPieceCompatibleEquals());
+#endif
+}
+
+#endif // UTIL_STRING_PIECE_HASH__