operator==,!=,<,<=,>,>=,<=>(std::sub_match)

From cppreference.com
< cpp‎ | regex‎ | sub match
C++
Text processing library
Regular expressions library
Classes
(C++11)
(C++11)
(C++11)
Algorithms
(C++11)
(C++11)
(C++11)
Iterators
(C++11)
(C++11)
Exceptions
(C++11)
Traits
(C++11)
Constants
(C++11)
(C++11)
(C++11)
Regex Grammar
(C++11)
std::sub_match
Member functions
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)
Defined in header <regex>
Direct comparison
template < class BidirIt >

bool operator== ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(1) (since C++11)
template < class BidirIt >

bool operator! = ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(2) (since C++11)
(until C++20)
template < class BidirIt >

bool operator< ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(3) (since C++11)
(until C++20)
template < class BidirIt >

bool operator<= ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(4) (since C++11)
(until C++20)
template < class BidirIt >

bool operator> ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(5) (since C++11)
(until C++20)
template < class BidirIt >

bool operator>= ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(6) (since C++11)
(until C++20)
template < class BidirIt >

auto operator<=> ( const std::sub_match <BidirIt> & lhs,

const std::sub_match <BidirIt> & rhs ) ;
(7) (since C++20)
Comparing with a std::basic_string
template < class BidirIt, class Traits, class Alloc >

bool operator== ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(8) (since C++11)
template < class BidirIt, class Traits, class Alloc >

bool operator! = ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(9) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator< ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(10) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator<= ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(11) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator> ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(12) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator>= ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(13) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

auto operator<=> ( const std::sub_match <BidirIt> & lhs,
const std::basic_string < /*value-type-of*/ <BidirIt>,

                                          Traits, Alloc> & str ) ;
(14) (since C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator== ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(15) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator! = ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(16) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator< ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(17) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator<= ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(18) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator> ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(19) (since C++11)
(until C++20)
template < class BidirIt, class Traits, class Alloc >

bool operator>= ( const std::basic_string < /*value-type-of*/ <BidirIt>,
                                          Traits, Alloc> & str,

const std::sub_match <BidirIt> & rhs ) ;
(20) (since C++11)
(until C++20)
Comparing with a C-style string
template < class BidirIt >

bool operator== ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(21) (since C++11)
template < class BidirIt >

bool operator! = ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(22) (since C++11)
(until C++20)
template < class BidirIt >

bool operator< ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(23) (since C++11)
(until C++20)
template < class BidirIt >

bool operator<= ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(24) (since C++11)
(until C++20)
template < class BidirIt >

bool operator> ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(25) (since C++11)
(until C++20)
template < class BidirIt >

bool operator>= ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(26) (since C++11)
(until C++20)
template < class BidirIt >

auto operator<=> ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> * s ) ;
(27) (since C++20)
template < class BidirIt >

bool operator== ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(28) (since C++11)
(until C++20)
template < class BidirIt >

bool operator! = ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(29) (since C++11)
(until C++20)
template < class BidirIt >

bool operator< ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(30) (since C++11)
(until C++20)
template < class BidirIt >

bool operator<= ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(31) (since C++11)
(until C++20)
template < class BidirIt >

bool operator> ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(32) (since C++11)
(until C++20)
template < class BidirIt >

bool operator>= ( const /*value-type-of*/ <BidirIt> * s,

const std::sub_match <BidirIt> & rhs ) ;
(33) (since C++11)
(until C++20)
Comparing with a single character
template < class BidirIt >

bool operator== ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(34) (since C++11)
template < class BidirIt >

bool operator! = ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(35) (since C++11)
(until C++20)
template < class BidirIt >

bool operator< ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(36) (since C++11)
(until C++20)
template < class BidirIt >

bool operator<= ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(37) (since C++11)
(until C++20)
template < class BidirIt >

bool operator> ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(38) (since C++11)
(until C++20)
template < class BidirIt >

bool operator>= ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(39) (since C++11)
(until C++20)
template < class BidirIt >

auto operator<=> ( const std::sub_match <BidirIt> & lhs,

const /*value-type-of*/ <BidirIt> & ch ) ;
(40) (since C++20)
template < class BidirIt >

bool operator== ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(41) (since C++11)
(until C++20)
template < class BidirIt >

bool operator! = ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(42) (since C++11)
(until C++20)
template < class BidirIt >

bool operator< ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(43) (since C++11)
(until C++20)
template < class BidirIt >

bool operator<= ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(44) (since C++11)
(until C++20)
template < class BidirIt >

bool operator> ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(45) (since C++11)
(until C++20)
template < class BidirIt >

bool operator>= ( const /*value-type-of*/ <BidirIt> & ch,

const std::sub_match <BidirIt> & rhs ) ;
(46) (since C++11)
(until C++20)
Helper type aliases
template < class BidirIt >

using /*value-type-of*/ =

typename std::iterator_traits <BidirIt> :: value_type ;
(47) (exposition only*)
template < class BidirIt >

using /*cat-type-of*/ =
std::compare_three_way_result_t

< std::basic_string < /*value-type-of*/ <BidirIt>>> ;
(48) (since C++20)
(exposition only*)

Compares a sub_match to another sub_match, a std::string, a C-style string or a single character.

1-7) Compares two sub_match directly.
8-20) Compares a sub_match with a std::basic_string.
21-33) Compares a sub_match with a C-style string.
34-46) Compares a sub_match with a single character.

The <, <=, >, >=, and != operators are synthesized from operator<=> and operator==

(since C++20)
47) value-type-of <BidirIt> is the value type of BidirIt
48) cat-type-of <BidirIt> is the result type of three-way comparison of std::sub_match<BidirIt>

Parameters

lhs, rhs - a sub_match to compare
str - a std::basic_string to compare
s - a pointer to a C-style string to compare
ch - a character to compare

Return value

Let target be the following values:

1-7) rhs
8-20) typename std::sub_match <BidirIt> :: string_type (str.data ( ), str.size ( ) )
21-33) s
34-46) typename std::sub_match <BidirIt> :: string_type ( 1, ch)

The return values are defined as follows:

Operator  Return value
Overloads (1-14,21-27,34-40)
(overloads with parameter lhs) 		Overloads (15-20,28-33,41-46)
(overloads without parameter lhs)
== lhs.compare(target) == 0 rhs.compare(target) == 0
!= lhs.compare(target) != 0 rhs.compare(target) != 0
< lhs.compare(target) < 0 rhs.compare(target) > 0
<= lhs.compare(target) <= 0 rhs.compare(target) >= 0
> lhs.compare(target) > 0 rhs.compare(target) < 0
>= lhs.compare(target) >= 0 rhs.compare(target) <= 0
<=> static_cast< cat-type-of <BidirIt>>
(lhs.compare (target) <=> 0 ) 		N/A

Notes

The return type of operator<=> is guaranteed to be a comparison category type. If value-type-of <BidirIt> is char, wchar_t, char8_t, char16_t, or char32_t, the return type of operator<=> is std::strong_ordering

Example

This section is incomplete
Reason: no example

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2217 C++11 for comparisons with std::string, the
argument of compare() was str.c_str() 		the argument is
string_type(str.data ( ), str.size ( ) ) )

See also

 compares matched subsequence (if any)
(public member function)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/regex/sub_match/operator_cmp&oldid=177695