Substring Extraction: Owning String vs String View

Question 43 / 51 • Correct so far: 0 (0 answered)

Snippet A

String Substr

std::size_t sumSubstrLengths(const std::string& src, std::size_t subLen) {
    std::size_t total = 0;
    for (std::size_t i = 0; i + subLen <= src.size(); i += subLen) {
        std::string sub = src.substr(i, subLen);
        total += sub.size();
    }
    return total;
}

std::size_t n = sumSubstrLengths(SOURCE, kSubLen);
Snippet B

View Substr

std::size_t sumSubstrLengths(std::string_view src, std::size_t subLen) {
    std::size_t total = 0;
    for (std::size_t i = 0; i + subLen <= src.size(); i += subLen) {
        std::string_view sub = src.substr(i, subLen);
        total += sub.size();
    }
    return total;
}

std::size_t n = sumSubstrLengths(SOURCE_VIEW, kSubLen);
Shared test data (shared-setup) 
static const std::string SOURCE = []() {
    std::string s;
    s.reserve(1024);
    for (int i = 0; i < 64; ++i)
        s += "word" + std::to_string(i) + " ";
    return s;
}();
static const std::string_view SOURCE_VIEW{SOURCE};
constexpr std::size_t kSubLen = 8;

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