NAME¶

std::regex_iterator::regex_iterator - std::regex_iterator::regex_iterator

Synopsis¶

regex_iterator(); (1) (since C++11)
regex_iterator( BidirIt a, BidirIt b,

const regex_type& re, (2) (since C++11)
std::regex_constants::match_flag_type m =

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

const regex_type&&, (4) (since C++11)
std::regex_constants::match_flag_type =

std::regex_constants::match_default ) = delete;

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{"#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 - overload (4) is deleted
};

for (decltype(it) last /* overload (1) */; it != last; ++it)
std::cout << (*it).str();
}

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
a regex_iterator constructed
LWG 2332 C++11 from a temporary such construction is disallowed via
basic_regex became invalid a deleted overload
immediately