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std::basic_string::find_last_of

size_type find_last_of( const basic_string& str, size_type pos = npos ) const;	(1)
size_type find_last_of( const CharT* s, size_type pos, size_type count ) const;	(2)
size_type find_last_of( const CharT* s, size_type pos = npos ) const;	(3)
size_type find_last_of( CharT ch, size_type pos = npos ) const;	(4)
template < class T > size_type find_last_of( const T& t, size_type pos = npos ) const;	(5)	(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 [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 the first count characters of the character string pointed to by s. s 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.

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 only participates in overload resolution if std::is_convertible_v<const T&, std::basic_string_view<CharT, Traits>> is true and std::is_convertible_v<const T&, 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

1-4) (none)	(until C++11)
1,4) `noexcept` specification: `noexcept` 2,3) (none)	(since C++11) (until C++14)
1) `noexcept` specification: `noexcept` 2,3,4) (none)	(since C++14)
5) Throws nothing unless the initialization of `sv` throws an exception.	(since C++17)

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 2946	C++17	`string_view` overload causes ambiguity in some cases	avoided by making it a template

Example

#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