# std::basic_string_view<CharT,Traits>::contains

From cppreference.com
< cpp‎ | string‎ | basic string view

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.

### 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.

### Notes

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

### Example

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

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