Difference between revisions of "cpp/regex/regex match"
(+details on the match results) |
m (Text replace - "BidirectionalIterator" to "BidirIt") |
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{{ddcl list header | regex}} | {{ddcl list header | regex}} | ||
{{ddcl list item | num=1 | notes={{mark since c++11}} | 1= | {{ddcl list item | num=1 | notes={{mark since c++11}} | 1= | ||
| − | template< class | + | template< class BidirIt, |
class Alloc, class CharT, class Traits > | class Alloc, class CharT, class Traits > | ||
| − | bool regex_match( | + | bool regex_match( BidirIt first, BidirIt last, |
| − | std::match_results< | + | std::match_results<BidirIt,Alloc>& m, |
const std::basic_regex<CharT,Traits>& e, | const std::basic_regex<CharT,Traits>& e, | ||
std::regex_constants::match_flag_type flags = | std::regex_constants::match_flag_type flags = | ||
| Line 13: | Line 13: | ||
}} | }} | ||
{{ddcl list item | num=2 | notes={{mark since c++11}} | 1= | {{ddcl list item | num=2 | notes={{mark since c++11}} | 1= | ||
| − | template< class | + | template< class BidirIt, |
class CharT, class Traits > | class CharT, class Traits > | ||
| − | bool regex_match( | + | bool regex_match( BidirIt first, BidirIt last, |
const std::basic_regex<CharT,Traits>& e, | const std::basic_regex<CharT,Traits>& e, | ||
std::regex_constants::match_flag_type flags = | std::regex_constants::match_flag_type flags = | ||
Revision as of 03:00, 3 August 2012
Template:ddcl list begin <tr class="t-dsc-header">
<td><regex>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td > class Alloc, class CharT, class Traits >
bool regex_match( BidirIt first, BidirIt last,
std::match_results<BidirIt,Alloc>& m,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (1) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">
<td > class CharT, class Traits >
bool regex_match( BidirIt first, BidirIt last,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (2) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">
<td >bool regex_match( const CharT* str,
std::match_results<const CharT*,Alloc>& m,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (3) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">
<td > class Alloc, class CharT, class Traits >
bool regex_match( const std::basic_string<CharT,STraits,SAlloc>& s,
std::match_results<
typename std::basic_string<CharT,STraits,SAlloc>::const_iterator,
Alloc
>& m,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (4) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">
<td >bool regex_match( const CharT* str,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (5) </td> <td > (since C++11) </td> </tr> <tr class="t-dcl ">
<td > class CharT, class Traits >
bool regex_match( const std::basic_string<CharT, STraits, SAlloc>& s,
const std::basic_regex<CharT,Traits>& e,
std::regex_constants::match_flag_type flags =
<td > (6) </td> <td > (since C++11) </td> </tr> Template:ddcl list end
1) Determines if there is a match between the regular expression e and the entire target character sequence [first,last), taking into account the effect of flags. Match results are returned in m.
2) Behaves as (1) above, omitting the match results.
3) Returns std::regex_match(str, str + std::char_traits<charT>::length(str), m, e, flags).
4) Returns std::regex_match(s.begin(), s.end(), m, e, flags).
5) Returns std::regex_match(str, str + std::char_traits<charT>::length(str), e, flags).
6) Returns std::regex_match(s.begin(), s.end(), e, flags).
Contents |
Parameters
| first, last | - | the target character range to apply the regex to, given as iterators |
| m | - | the match results |
| str | - | the target string, given as a null-terminated C-style string |
| s | - | the target string, given as a std::basic_string |
| e | - | the regular expression |
| flags | - | flags used to determine how the match will be performed |
Return value
Returns true if a match exists, false otherwise. In either case, the object m is updated, as follows:
If the match does not exist:
| m.ready() == true | |
| m.empty() == true | |
| m.size() == 0 |
If the match exists:
| m.ready() | true |
| m.empty() | false |
| m.size() | number of subexpressions plus 1, that is, 1+e.mark_count() |
| m.prefix().first | first
|
| m.prefix().second | first
|
| m.prefix().matched | false (the match prefix is empty) |
| m.suffix().first | last
|
| m.suffix().second | last
|
| m.suffix().matched | false (the match suffix is empty) |
| m[0].first | first
|
| m[0].second | last
|
| m[0].matched | true (the entire sequence is matched) |
| m[n].first | the start of the sequence that matched sub-expression n, or last if the subexpression did not participate in the match
|
| m[n].second | the end of the sequence that matched sub-expression n, or last if the subexpression did not participate in the match
|
| m[n].matched | true if sub-expression n participated in the match, false otherwise |
Example
#include <iostream> #include <string> #include <regex> int main() { std::string fnames[] = {"foo.txt", "bar.txt", "zoidberg"}; std::regex txt_regex("[a-z]+\\.txt"); for (const auto &fname : fnames) { std::cout << fname << ": " << std::regex_match(fname, txt_regex) << '\n'; } }
Output:
foo.txt: 1 bar.txt: 1 zoidberg: 0
