operator< <regex>
Less than comparison for various objects.
template<class BidIt>
bool operator<(const sub_match<BidIt>& left,
const sub_match<BidIt>& right);
template<class BidIt, class IOtraits, class Alloc>
bool operator<(
const basic_string<typename iterator_traits<BidIt>::value_type, IOtraits, Alloc>& left,
const sub_match<BidIt>& right);
template<class BidIt, class IOtraits, class Alloc>
bool operator<(const sub_match<BidIt>& left,
const basic_string<typename iterator_traits<BidIt>::value_type, IOtraits, Alloc>& right);
template<class BidIt>
bool operator<(const typename iterator_traits<BidIt>::value_type *left,
const sub_match<BidIt>& right);
template<class BidIt>
bool operator<(const sub_match<BidIt>& left,
const typename iterator_traits<BidIt>::value_type *right);
template<class BidIt>
bool operator<(const typename iterator_traits<BidIt>::value_type& left,
const sub_match<BidIt>& right);
template<class BidIt>
bool operator<(const sub_match<BidIt>& left,
const typename iterator_traits<BidIt>::value_type& right);
Parameters
BidIt
The iterator type.IOtraits
The string traits class.Alloc
The allocator class.left
The left object to compare.right
The right object to compare.
Remarks
Each template operator converts its arguments to a string type and returns true only if the converted value of left compares less than the converted value of right.
Example
// std_tr1__regex__operator_lt.cpp
// compile with: /EHsc
#include <regex>
#include <iostream>
typedef std::cmatch::string_type Mystr;
int main()
{
std::regex rx("c(a*)|(b)");
std::cmatch mr;
std::regex_search("xcaaay", mr, rx);
std::csub_match sub = mr[1];
std::cout << "sub == " << sub << std::endl;
std::cout << std::endl;
std::cout << "sub < sub == " << std::boolalpha
<< (sub < sub) << std::endl;
std::cout << "string(\"aab\") < sub == " << std::boolalpha
<< (Mystr("aab") < sub) << std::endl;
std::cout << "sub < string(\"aab\") == " << std::boolalpha
<< (sub < Mystr("aab")) << std::endl;
std::cout << "\"aab\" < sub == " << std::boolalpha
<< ("aab" < sub) << std::endl;
std::cout << "sub < \"aab\" == " << std::boolalpha
<< (sub < "aab") << std::endl;
std::cout << "'a' < sub == " << std::boolalpha
<< ('a' < sub) << std::endl;
std::cout << "sub < 'a' == " << std::boolalpha
<< (sub < 'a') << std::endl;
return (0);
}
sub == aaa
sub < sub == false
string("aab") < sub == false
sub < string("aab") == true
"aab" < sub == false
sub < "aab" == true
'a' < sub == true
sub < 'a' == false
Requirements
Header: <regex>
Namespace: std