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

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 Comment
__cpp_lib_string_contains 202011L (C++23) contains functions

Example

#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

(C++20)
 checks if the string view starts with the given prefix
(public member function)
(C++20)
 checks if the string view ends with the given suffix
(public member function)
(C++17)
 find characters in the view
(public member function)
(C++17)
 returns a substring
(public member function)
(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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