NAME¶

std::basic_string::find_last_of - std::basic_string::find_last_of

Synopsis¶

size_type find_last_of( const (until
basic_string& str, C++11)
size_type pos = npos ) const;
constexpr size_type find_last_of( (since
const basic_string& str, C++11)
size_type pos = npos ) const (until
noexcept; C++20)
size_type find_last_of( const CharT*
s, (until
size_type pos, size_type count ) C++11)
const;
constexpr size_type find_last_of(
const CharT* s, (since
size_type pos, size_type count ) C++11)
const;
size_type find_last_of( const CharT* (until
s, size_type pos = npos ) const; C++20)
constexpr size_type find_last_of( (since
const CharT* s, size_type pos = npos C++20)
) const;
size_type find_last_of( CharT ch, (until
size_type pos = npos ) const; C++11)
size_type find_last_of( CharT ch, (1) (since
size_type pos = npos ) const C++11)
noexcept; (until
C++20)
constexpr size_type find_last_of( (2)
CharT ch, (since
size_type pos = npos ) const C++20)
noexcept;
template < class StringViewLike > (3)

size_type (4) (since
find_last_of( const StringViewLike& C++17)
t, (until
C++20)
size_type pos = npos ) const
noexcept(/* see below */); (5)
template < class StringViewLike >

constexpr size_type
find_last_of( const StringViewLike& (since
t, C++20)

size_type pos = npos ) const
noexcept(/* see below */);

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

1) Finds the last character equal to one of characters in str.
2) Finds the last character equal to one of characters in range [s, s+count). This
range can include null characters.
3) Finds the last character equal to one of characters in character string pointed
to by s. The length of the string is determined by the first null character using
Traits::length(s).
4) Finds the last character equal to ch.
5) Implicitly converts t to a string view sv as if by std::basic_string_view<CharT,
Traits> sv = t;, then finds the last character equal to one of characters in sv.
This overload participates in overload resolution only if
std::is_convertible_v<const StringViewLike&, std::basic_string_view<CharT, Traits>>
is true and std::is_convertible_v<const StringViewLike&, const CharT*> is false.

In all cases, equality is checked by calling Traits::eq.

Parameters¶

str - string identifying characters to search for
pos - position at which the search is to finish
count - length of character string identifying characters to search for
s - pointer to a character string identifying characters to search for
ch - character to search for
t - object (convertible to std::basic_string_view) identifying characters to
search for

Return value¶

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

Exceptions¶

5)
noexcept specification:
noexcept(std::is_nothrow_convertible_v<const T&, std::basic_string_view<CharT,
Traits>>)

Example¶

// Run this code

#include<string>
#include<iostream>
int main()
{
const std::string path="/root/config";
auto const pos=path.find_last_of('/');
const auto leaf=path.substr(pos+1);

std::cout << leaf << '\n';
}

Output:¶

config

Defect reports

The following behavior-changing defect reports were applied retroactively to
previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2064 C++11 overload (3) and (4) were noexcept removed
LWG 2946 C++17 string_view overload causes ambiguity in avoided by making it a
some cases template
P1148R0 C++11 noexcept for overload (4)/(5) was restored
C++17 accidently dropped by LWG2064/LWG2946

See also¶

find find characters in the string
(public member function)
rfind find the last occurrence of a substring
(public member function)
find_first_of find first 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_last_of find last occurrence of characters
(C++17) (public member function of std::basic_string_view<CharT,Traits>)