std::match_results<BidirIt,Alloc>::ready

 

C++

Compiler support

Freestanding and hosted

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Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

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Input/output library

Filesystem library (C++17)

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Technical specifications

Symbols index

External libraries

 

Regular expressions library

Classes

basic_regex (C++11)

sub_match (C++11)

match_results (C++11)

Algorithms

regex_match (C++11)

regex_search (C++11)

regex_replace (C++11)

Iterators

regex_iterator (C++11)

regex_token_iterator (C++11)

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regex_error (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::match_results

Member functions

match_results::match_results

match_results::~match_results

match_results::operator=

match_results::get_allocator

State

match_results::ready

Element access

match_results::size

match_results::max_size

match_results::empty

match_results::length

match_results::position

match_results::str

match_results::operator[]

match_results::prefix

match_results::suffix

Iterators

match_results::beginmatch_results::cbegin

match_results::endmatch_results::cend

Format

match_results::format

Modifiers

match_results::swap

Non-member functions

operator==operator!= (until C++20)

swap(std::match_results)

 

bool ready() const;		(since C++11)

Indicates if the match results are ready (valid) or not.

A default-constructed match result has no result state (is not ready), and can only be made ready by one of the regex algorithms. The ready state implies that all match results have been fully established.

The result of calling most member functions of the match_results object that is not ready is undefined.

Return value

true if the match results are ready, false otherwise.

Example

Run this code

#include <iostream>
#include <regex>
#include <string>
 
int main()
{
    std::string target("pattern");
    std::smatch sm;
    std::cout << "default constructed smatch is "
              << (sm.ready() ? "ready\n" : "not ready\n");
 
    std::regex re1("tte");
    std::regex_search(target, sm, re1);
 
    std::cout << "after search, smatch is "
              << (sm.ready() ? "ready\n" : "not ready\n");
}

Output:

default constructed smatch is not ready
after search, smatch is ready