operator<<(std::sub_match)

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Diagnostics library

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Metaprogramming library (C++11)

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Containers library

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Technical specifications

Symbols index

External libraries

 

Text processing library

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Regular expressions library (C++11)

Formatting library (C++20)

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to_chars (C++17) to_chars_result (C++17) from_chars (C++17) from_chars_result (C++17) chars_format (C++17)

Text encoding identifications

text_encoding (C++26)

 

Regular expressions library

Classes

basic_regex (C++11)

sub_match (C++11)

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regex_match (C++11)

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regex_traits (C++11)

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syntax_option_type (C++11)

match_flag_type (C++11)

error_type (C++11)

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Modified ECMAScript-262 (C++11)

 

std::sub_match

Member functions

sub_match::sub_match

sub_match::length

sub_match::strsub_match::operator string_type

sub_match::compare

sub_match::swap

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<<

 

template< class CharT, class Traits, class BidirIt > std::basic_ostream<CharT,Traits>&     operator<<( std::basic_ostream<CharT,Traits>& os, const sub_match<BidirIt>& m );		(since C++11)

Writes the representation of the matched subsequence m to the output stream os. Equivalent to os << m.str().

Parameters

os	-	output stream to write the representation to
m	-	a sub-match object to output

Return value

os

Example

Run this code

#include <iostream>
#include <regex>
#include <string>
 
int main()
{
    std::string sentence{"Quick red fox jumped over a lazy hare."};
    const std::regex re{"([A-z]+) ([a-z]+) ([a-z]+)"};
    std::smatch words;
    std::regex_search(sentence, words, re);
    for (const auto& m : words)
        / m has type `const std::sub_match<std::string::const_iterator>&`
        std::cout << '[' << m << "] ";
    std::cout << '\n';
}

Output:

[Quick red fox] [Quick] [red] [fox]

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