mosesdecoder/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__