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

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< cpp‎ | string‎ | basic string view

constexpr size_type find( basic_string_view v, size_type pos = 0 ) const noexcept; | (1) | (since C++17)
constexpr size_type find( CharT ch, size_type pos = 0 ) const noexcept; | (2) | (since C++17)
constexpr size_type find( const CharT* s, size_type pos, size_type count ) const; | (3) | (since C++17)
constexpr size_type find( const CharT* s, size_type pos = 0 ) const; | (4) | (since C++17)

Finds the first substring equal to the given character sequence.

1) Finds the first occurence of v in this view, starting at position pos.
2) Equivalent to find(basic_string_view( std::addressof (ch), 1), pos).
3) Equivalent to find(basic_string_view(s, count), pos).
4) Equivalent to find(basic_string_view(s), pos).

### Parameters

v | - | view to search for
pos | - | position at which to start the search
count | - | length of substring to search for
s | - | pointer to a character string to search for
ch | - | character to search for

### Return value

Position of the first character of the found substring, or npos if no such substring is found.

### Complexity

O(size() * v.size()) at worst.

### Example

Run this code

    #include <string_view>

    int main()
    {
        using namespace std::literals;

        constexpr auto str{" long long int;"sv};

        static_assert(
            1 == str.find("long"sv)            && "<- find(v , pos = 0)" &&
            6 == str.find("long"sv, 2)         && "<- find(v , pos = 2)" &&
            0 == str.find(' ')                 && "<- find(ch, pos = 0)" &&
            2 == str.find('o', 1)              && "<- find(ch, pos = 1)" &&
            2 == str.find("on")                && "<- find(s , pos = 0)" &&
            6 == str.find("long double", 5, 4) && "<- find(s , pos = 5, count = 4)"
        );

        static_assert(str.npos == str.find("float"));
    }

### See also

rfind | find the last occurrence of a substring (public member function)
find_first_of | find first occurrence of characters (public member function)
find_last_of | find last occurrence of characters (public member function)
find_first_not_of | find first absence of characters (public member function)
find_last_not_of | find last absence of characters (public member function)
find | finds the first occurrence of the given substring (public member function of `std::basic_string<CharT,Traits,Allocator>`)

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