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

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< cpp‎ | string‎ | basic string view

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

Finds the first character not equal to any of the characters in the given character sequence.

1) Finds the first character not equal to any of the characters of v in this view, starting at position pos.
2) Equivalent to find_first_not_of(basic_string_view(std::addressof(ch), 1), pos).
3) Equivalent to find_first_not_of(basic_string_view(s, count), pos).
4) Equivalent to find_first_not_of(basic_string_view(s), pos).

### Parameters

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

### Return value

Position of the first character not equal to any of the characters in the given string, or std::string_view::npos if no such character is found.

### Complexity

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

### Example

Run this code

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

    int main()
    {
        static_assert(2 == "BCDEF"sv.find_first_not_of("ABC"));
                        //    ^
        static_assert(4 == "BCDEF"sv.find_first_not_of("ABC", 4));
                        //      ^
        static_assert(1 == "BCDEF"sv.find_first_not_of('B'));
                        //   ^
        static_assert(3 == "BCDEF"sv.find_first_not_of('D', 2));
                        //     ^
    }

### See also

find (C++17) | find characters in the view (public member function)
rfind (C++17) | find the last occurrence of a substring (public member function)
find_first_of (C++17) | find first occurrence of characters (public member function)
find_last_of (C++17) | find last occurrence of characters (public member function)
find_last_not_of (C++17) | find last absence of characters (public member function)
find_first_not_of | find first absence of characters (public member function of `std::basic_string<CharT,Traits,Allocator>`)

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