std::match_...:operator[](3)

💅 std::match_results::operator[] — C++ Standard Library manual page ✨

okay bestie, this is the C++ Standard Library manual page for std::match_results::operator[], and it is literally the member that gives you a std::sub_match reference when you index into your match results. icon behavior, regex girlie. 🎀

🦋 NAME 🦋

std::match_results::operator[] — yes, that is the whole name, and no, we are not skipping the intro. periodt.

✨ Synopsis ✨

const_reference operator[]( size_type n ) const;  (since C++11)

Here's the vibe check on what each index gets you:

• If n > 0 and n < size(), it returns a reference to the std::sub_match representing the part of the target sequence that was matched by the n^th captured marked subexpression. 🔥
• If n == 0, it returns a reference to the std::sub_match representing the part of the target sequence matched by the entire matched regular expression. main character match energy.
• If n >= size(), it returns a reference to a std::sub_match representing an unmatched sub-expression — which is an empty subrange of the target sequence. 💀
• The behavior is undefined unless ready() == true.

🚨 bestie, seriously: the behavior is undefined unless ready() == true. That is not a cute little edge case, that is a hard no. 🙈

🌸 Parameters 🌸

• n — an integral number specifying which match to return. it's giving "which one, bestie?" 💅

🫶 Return value 🫶

A reference to the std::sub_match representing the specified matched subrange within the target sequence. slay. ✨

🍓 Example 🍓

        #include <iostream>
        #include <regex>
        #include <string>

        int main()
        {
            std::string target("baaaby");
            std::smatch sm;

            std::regex re1("a(a)*b");
            std::regex_search(target, sm, re1);
            std::cout << "entire match: " << sm[0] << '\n'
                      << "submatch #1: " << sm[1] << '\n';

            std::regex re2("a(a*)b");
            std::regex_search(target, sm, re2);
            std::cout << "entire match: " << sm[0] << '\n'
                      << "submatch #1: " << sm[1] << '\n';
        }

🌈 Output 🌈

        entire match: aaab
        submatch #1: a
        entire match: aaab
        submatch #1: aa

👑 See also 👑

• str — returns the sequence of characters for the particular sub-match (public member function). the supporting character that also ate. 💜

mwah 💋 — this page is serving C++ Standard Library manual realness from http://cppreference.com, dated 2024.06.10. go off, regex bestie. 🧚‍♀️⭐