std::match_results::length

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

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)

Exceptions

regex_error (C++11)

Traits

regex_traits (C++11)

Constants

syntax_option_type (C++11)

match_flag_type (C++11)

error_type (C++11)

Regex Grammar

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

difference_type length( size_type n = 0 ) const;		(since C++11)

Returns the length of the specified sub-match.

If n == 0, the length of the entire matched expression is returned.

If n > 0 && n < size(), the length of nth sub-match is returned.

if n >= size(), a length of the unmatched match is returned.

The call is equivalent to (*this)[n].length().

Parameters

n

-

integral number specifying which match to examine

Return value

The length of the specified match or sub-match.

See also

operator[]	returns specified sub-match (public member function)
length	returns the length of the match (if any) (public member function of std::sub_match)