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

From cppreference.com
 
 
 
 
constexpr size_type
    find_last_of( basic_string_view v, size_type pos = npos ) const noexcept;
(1) (since C++17)
constexpr
    size_type find_last_of( CharT ch, size_type pos = npos ) const noexcept;
(2) (since C++17)
constexpr
    size_type find_last_of( const CharT* s, size_type pos, size_type count ) const;
(3) (since C++17)
constexpr
    size_type find_last_of( const CharT* s, size_type pos = npos ) const;
(4) (since C++17)

Finds the last character equal to one of characters in the given character sequence. Exact search algorithm is not specified. The search considers only the interval [0pos]. If the character is not present in the interval, npos will be returned.

1) Finds the last occurence of any of the characters of v in this view, ending at position pos.
2) Equivalent to find_last_of(basic_string_view(std::addressof(ch), 1), pos).
3) Equivalent to find_last_of(basic_string_view(s, count), pos).
4) Equivalent to find_last_of(basic_string_view(s), pos).

Parameters

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

Return value

Position of the last occurrence of any character of the substring, or npos if no such character is found.

Complexity

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

Example

#include <iostream>
#include <string_view>
 
int main()
{
  using namespace std::literals;
  constexpr auto N = std::string_view::npos;
 
  static_assert(
    5 == "delete"sv.find_last_of("cdef"sv) &&
      //       └────────────────────┘
    N == "double"sv.find_last_of("fghi"sv) &&
      //
    0 == "else"sv.find_last_of("bcde"sv, 2 /* pos [0..2]: "els" */) &&
      //  └────────────────────────┘
    N == "explicit"sv.find_last_of("abcd"sv, 4 /* pos [0..4]: "expli" */) &&
      //
    3 == "extern"sv.find_last_of('e') &&
      //     └────────────────────┘
    N == "false"sv.find_last_of('x') &&
      //
    0 == "inline"sv.find_last_of('i', 2 /* pos [0..2]: "inl" */) &&
      //  └───────────────────────┘
    N == "mutable"sv.find_last_of('a', 2 /* pos [0..2]: "mut" */) &&
      //
    3 == "namespace"sv.find_last_of("cdef", 3 /* pos [0..3]: "name" */, 3 /* "cde" */) &&
      //     └─────────────────────────┘
    N == "namespace"sv.find_last_of("cdef", 3 /* pos [0..3]: "name" */, 2 /* "cd" */)
  );
 
  std::cout << "All tests passed.\n";
}

Output:

All tests passed.

See also

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