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

 

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Strings library

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basic_string

basic_string_view (C++17)

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std::basic_string_view

Member functions basic_string_view::basic_string_view    basic_string_view::operator= Iterators basic_string_view::beginbasic_string_view::cbegin basic_string_view::endbasic_string_view::cend basic_string_view::rbeginbasic_string_view::crbegin basic_string_view::rendbasic_string_view::crend Capacity basic_string_view::sizebasic_string_view::length basic_string_view::max_size basic_string_view::empty Operations basic_string_view::copy basic_string_view::substr basic_string_view::compare basic_string_view::starts_with (C++20) basic_string_view::ends_with (C++20) basic_string_view::contains (C++23) basic_string_view::find basic_string_view::rfind basic_string_view::find_first_of basic_string_view::find_last_of basic_string_view::find_first_not_of basic_string_view::find_last_not_of

Element access basic_string_view::at basic_string_view::operator[] basic_string_view::front basic_string_view::back basic_string_view::data Modifiers basic_string_view::remove_prefix basic_string_view::remove_suffix basic_string_view::swap Constants basic_string_view::npos Non-member functions operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20) operator<< operator""sv Helper classes hash<std::string_view>hash<std::wstring_view>hash<std::u8string_view>hash<std::u16string_view>hash<std::u32string_view> (C++20) Deduction guides (C++20)

 

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

Finds the last substring that is equal to the given character sequence. The search begins at pos and proceeds from right to left (thus, the found substring, if any, cannot begin in a position following pos). If npos or any value not smaller than size() - 1 is passed as pos, the whole string will be searched.

1) Finds the last occurrence of v in this view, starting at position pos.

2) Equivalent to rfind(basic_string_view(std::addressof(ch), 1), pos).

3) Equivalent to rfind(basic_string_view(s, count), pos).

4) Equivalent to rfind(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 N = std::string_view::npos;
 
    static_assert(true
        && (6 == "AB AB AB"sv.rfind("AB"))
        && (6 == "AB AB AB"sv.rfind("ABCD", N, 2))
        && (3 == "AB AB AB"sv.rfind("AB", 5))
        && (0 == "AB CD EF"sv.rfind("AB", 0))
        && (2 == "B AB AB "sv.rfind("AB", 2))
        && (N == "B AB AB "sv.rfind("AB", 1))
        && (5 == "B AB AB "sv.rfind('A'))
        && (4 == "AB AB AB"sv.rfind('B', 4))
        && (N == "AB AB AB"sv.rfind('C'))
    );
}

See also

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