std::basic_...w::contains(3)

hii bestie 💖 welcome to std::basic_...w::contains(3) from the C++ Standard Libary manual. this page is literally the std::basic_string_view::contains glow-up, and it's giving "tiny utility that checks a substring" ✨

✨ NAME ✨

std::basic_string_view::contains - std::basic_string_view::contains

📜 Synopsis 📜

okay so here's the synopsis, bestie — three overloads, all since C++23, and I kept every character:

constexpr bool contains( basic_string_view sv ) const noexcept; (1)
(since C++23)
constexpr bool contains( CharT c ) const noexcept;              (2)
(since C++23)
constexpr bool contains( const CharT* s ) const;                (3)
(since C++23)

Checks if the string view contains the given substring, where:

1. the substring is a string view.
2. the substring is a single character.
3. the substring is a null-terminated character string.

All three overloads are equivalent to return find(x) != npos;, where x is the parameter. periodt 💅

🧸 Parameters 🧸

• sv — a string view
• c — a single character
• s — a null-terminated character string

🎁 Return value 🎁

true if the string view contains the provided substring, false otherwise. no cap 🫶

📝 Notes 📝

feature-test macro check, bestie 🕵️‍♀️:

• Feature-test macro __cpp_lib_string_contains — Value 202011L — Std (C++23) — Feature contains functions

💻 Example 💻

run this code, it's a static_assert baddie and it slays:

// Run this code

#include <string_view>
using namespace std::literals;

static_assert
(
    // bool contains(basic_string_view x) const noexcept;
    "https://cppreference.com"sv.contains("cpp"sv) == true and
    "https://cppreference.com"sv.contains("php"sv) == false and

    // bool contains(CharT x) const noexcept;
    "C++23"sv.contains('+') == true and
    "C++23"sv.contains('-') == false and

    // bool contains(const CharT* x) const;
    std::string_view("basic_string_view").contains("string") == true
and
    std::string_view("basic_string_view").contains("String") == false
);

int main() {}

👀 See also 👀

• starts_with — checks if the string view starts with the given prefix (C++20) (public member function)
• ends_with — checks if the string view ends with the given suffix (C++20) (public member function)
• find — find characters in the view (public member function)
• substr — returns a substring (public member function)
• contains — checks if the string contains the given substring or character (C++23) (public member function of std::basic_string<CharT,Traits,Allocator>)

mwah 💋 that's the whole page — source/version http://cppreference.com, date 2024.06.10, and it's the std::basic_...w::contains(3) page. now go check your substrings, bestie 🫶