std::basic_string_view::find(3)

NAME
std::basic_string_view::find - std::basic_string_view::find

Synopsis
   constexpr size_type find( basic_string_view v, size_type pos = 0 ) (1) (since C++17)
   const noexcept;
   constexpr size_type find( CharT ch, size_type pos = 0 ) const (2) (since C++17)
   noexcept;
   constexpr size_type find( const CharT* s, size_type pos, size_type (3) (since C++17)
   count ) const;
   constexpr size_type find( const CharT* s, size_type pos = 0 ) (4) (since C++17)
   const;
   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)
                     finds the first occurrence of the given substring
   find (public member function of
                     std::basic_string<CharT,Traits,Allocator>)