utils::match_results Class Reference

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Table of Contents

• Detailed Description
• Public Member Functions
• Constructor & Destructor Documentation
• match_results()
• Member Function Documentation
• length()
• operator[]()
• position()
• prefix()
• size()
• suffix()
• Friends And Related Symbol Documentation
• regex_match
• regex_replace [1/2]
• regex_replace [2/2]
• regex_search

#include <userver/utils/regex.hpp>

Detailed Description

A drop-in replacement for std::match_results without huge includes and with better performance characteristics. Represents capturing groups of a single match result.

The group 0 always matches the whole pattern. User groups start with index 1.

Non-empty groups always point within the source string, so the position of a group within the source string can be obtained by subtracting .data() pointers or .begin() iterators.

Warning

The implementation can return empty groups as std::string_views with data() == nullptr or some invalid pointer with size() == 0. Check for emptiness before performing pointer arithmetic if a group can be empty according to the regex!

See also

utils::regex

Definition at line 97 of file regex.hpp.

Public Member Functions
	match_results ()
	match_results (const match_results &)
match_results &	operator= (const match_results &)
std::size_t	size () const
std::string_view	operator[] (std::size_t sub) const
std::size_t	position (std::size_t sub) const
std::size_t	length (std::size_t sub) const
std::string_view	prefix () const
std::string_view	suffix () const

Constructor & Destructor Documentation

match_results()

utils::match_results::match_results

(

)

Constructs a null match_results, any usage except for copy/move is UB. Filled upon successful regex_match or regex_search.

Member Function Documentation

length()

std::size_t utils::match_results::length

(

std::size_t

sub

)

const

Returns

the length of the capturing group at sub.

Note

Group 0 always matches the whole pattern. User groups start with index 1.

operator[]()

std::string_view utils::match_results::operator[]

(

std::size_t

sub

)

const

Returns

the capturing group at sub.

Note

Group 0 always matches the whole pattern. User groups start with index 1.

position()

std::size_t utils::match_results::position

(

std::size_t

sub

)

const

Returns

the position of the first character of the capturing group sub within the target (haystack) string.

Note

Group 0 always matches the whole pattern. User groups start with index 1.

Warning

For empty groups, calling this method is UB. Group 0 is always valid.

prefix()

std::string_view utils::match_results::prefix

(

)

const

Returns

the substring from the beginning of the target (haystack) string to the beginning of the full match.

size()

std::size_t utils::match_results::size

(

)

const

Returns

the number of capturing groups, including the group 0.

suffix()

std::string_view utils::match_results::suffix

(

)

const

Returns

the substring from the end of the full match to the end of the target (haystack) string.

Friends And Related Symbol Documentation

regex_match

bool regex_match ( std::string_view str, match_results & m, const regex & pattern )

friend

Returns true if the specified regular expression matches the whole of the input. Fills in what matched in m.

Note

m may be clobbered on failure.

regex_replace [1/2]

std::string regex_replace ( std::string_view str, const regex & pattern, Re2Replacement repl )

friend

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

See also

utils::Re2Replacement

regex_replace [2/2]

std::string regex_replace ( std::string_view str, const regex & pattern, std::string_view repl )

friend

Create a new string where all regular expression matches replaced with repl.

Interprets repl as a literal, does not support substitutions.

See also

utils::Re2Replacement

regex_search

bool regex_search ( std::string_view str, match_results & m, const regex & pattern )

friend

Determines whether the regular expression matches anywhere in the target character sequence. Fills in what matched in m.

Note

m may be clobbered on failure.

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The documentation for this class was generated from the following file:

• userver/utils/regex.hpp