| Localization library | |||||||||||||||||||||||||
| Regular expressions library(C++11) | |||||||||||||||||||||||||
| Formatting library(C++20) | |||||||||||||||||||||||||
| Null-terminated sequence utilities | |||||||||||||||||||||||||
| Byte strings | |||||||||||||||||||||||||
| Multibyte strings | |||||||||||||||||||||||||
| Wide strings | |||||||||||||||||||||||||
| Primitive numeric conversions | |||||||||||||||||||||||||
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| Text encoding identifications | |||||||||||||||||||||||||
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| Classes | ||||
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(C++11) | ||||
(C++11) | ||||
| Algorithms | ||||
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(C++11) | ||||
| Iterators | ||||
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| Exceptions | ||||
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| Traits | ||||
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| Constants | ||||
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| Regex Grammar | ||||
(C++11) |
| Member functions | ||||
| State | ||||
| Element access | ||||
match_results::position | ||||
| Iterators | ||||
| Format | ||||
| Modifiers | ||||
| Non-member functions | ||||
(until C++20) | ||||
difference_type position( size_type n=0)const; | (since C++11) | |
Returns the position of the first character of the specified sub-match.
Ifn==0, the position of the first character of the entire matched expression is returned.
Ifn>0&& n< size(), the position of the first character of thenth sub-match is returned.
ifn>= size(), a position of the first character of the unmatched match is returned.
ready() must betrue. Otherwise, the behavior is undefined.
Contents |
| n | - | integral number specifying which match to examine |
The position of the first character of the specified match or sub-match.
#include <iostream>#include <regex>#include <string> int main(){std::regex re("a(a)*b");std::string target("aaab");std::smatch sm; std::regex_match(target, sm, re);std::cout<< sm.position(1)<<'\n';}
Output:
2
| returns specified sub-match (public member function)[edit] |
