Function BuildLookupTable

base/string/string_piece.cpp:156–163

For each character in characters_wanted, sets the index corresponding to the ASCII code of that character to 1 in table. This is used by the m_find.*_of methods below to tell whether or not a character is in the lookup table in constant time. The argument `table' must be an array that is large enough to hold all the possible values of an unsigned char. Thus it should be be declared as follows: b

// as follows:
//   bool table[UCHAR_MAX + 1]
static inline void BuildLookupTable(const StringPiece& characters_wanted,
                                    bool* table) {
    const size_type length = characters_wanted.length();
    const char* const data = characters_wanted.data();
    for (size_type i = 0; i < length; ++i) {
        table[static_cast<unsigned char>(data[i])] = true;
    }
}

size_type StringPiece::find_first_of(const StringPiece& s,
                                     size_type pos) const {