std::regex_iterator<BidirIt,CharT,Traits>:: regex_iterator

From cppreference.com
C++
Regular expressions library
Classes
(C++11)
(C++11)
(C++11)
Algorithms
(C++11)
(C++11)
(C++11)
Iterators
(C++11)
(C++11)
Exceptions
(C++11)
Traits
(C++11)
Constants
(C++11)
(C++11)
(C++11)
Regex Grammar
(C++11)
std::regex_iterator
regex_iterator ( ) ;
(1) (since C++11)
regex_iterator ( BidirIt a, BidirIt b,

const regex_type & re,
std:: regex_constants :: match_flag_type m =

std:: regex_constants :: match_default ) ;
(2) (since C++11)
regex_iterator ( const regex_iterator & ) ;
(3) (since C++11)
regex_iterator ( BidirIt, BidirIt,

const regex_type && ,
std:: regex_constants :: match_flag_type =

std:: regex_constants :: match_default ) = delete ;
(4) (since C++11)

Constructs a new regex_iterator :

1) Default constructor. Constructs an end-of-sequence iterator.
2) Constructs a regex_iterator from the sequence of characters [ a , b ) , the regular expression re , and a flag m that governs matching behavior. This constructor performs an initial call to std::regex_search with this data. If the result of this initial call is false , * this is set to an end-of-sequence iterator.
3) Copies a regex_iterator .
4) The overload (2) is not allowed to be called with a temporary regex, since the returned iterator would be immediately invalidated.

Parameters

a - LegacyBidirectionalIterator to the beginning of the target character sequence
b - LegacyBidirectionalIterator to the end of the target character sequence
re - regular expression used to search the target character sequence
m - flags that govern the behavior of re

Example

Run this code 
#include <iostream>
#include <regex>
#include <string_view>
 
int main()
{
    constexpr std::string_view str{R"(
        #ONE: *p = &Mass;
        #Two: MOV %rd, 42
    )"};
    const std::regex re("[a-w]");
 
    // create regex_iterator, overload (2)
    auto it = std::regex_iterator<std::string_view::iterator>
    {
        str.cbegin(), str.cend(),
        re // re is lvalue; if an immediate expression was used
           // instead, e.g. std::regex{"[a-z]"}, this would
           // produce an error since overload (4) is deleted
    };
 
    for (decltype(it) last /* overload (1) */; it != last; ++it)
        std::cout << (*it).str();
    std::cout << '\n';
}

Output: 

password

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 2332 C++11 a regex_iterator constructed from a temporary
basic_regex became invalid immediately 		such construction is disallowed via a deleted overload
Retrieved from " https://en.cppreference.com/mwiki/index.php?title=cpp/regex/regex_iterator/regex_iterator&oldid=161422 "