boost::regex

 

match_results:

#include <regex>
 
template <
  typename BidirectionalIterator,
  typename Allocator = allocator<sub_match<BidirectionalIterator> >
> class match_results;

The class template match_results holds a collection of character sequences that represent the result of a regular expression match. Several specializations for common character sequence types are provided:

typedef match_results<const char*> cmatch;
typedef match_results<const wchar_t*> wcmatch;
typedef match_results<std::string::const_iterator> smatch;
typedef match_results<std::wstring::const_iterator> wsmatch;

字匹配的类型

wssub_match

csub_match
wcsub_match
ssub_match
Member types

Member type	Definition
sub_match<BidirectionalIterator>	value_type
const value_type&	const_reference
const_reference	reference
(implementation-defined)	const_iterator
const_iterator	iterator
typename iterator_traits<BidirectionalIterator>::difference_type	difference_type
typename allocator_traits<Allocator>::size_type	size_type
Allocator	allocator_type
typename iterator_traits<BidirectionalIterator>::value_type	char_type
std::basic_string<char_type>	string_type

Member functions

Constructors	create a match
Operators	assign values to a match
get_allocator	returns the allocator for this object
swap	swaps the matched sub-expressions with another match_results

Size

size	如果匹配成功，返回 1 + 匹配的子表达式个数
max_size	最多可存储子匹配的个数
empty	返回true 当有至少一个子匹配时，否则返回false

Element access

length	the length of a particular sub-expression
position	the distance between the start of the target sequence and a given sub-expression
str	the sequence of characters for a given sub-expression
operator_at	returns a reference to the sub_match for a specific sub-expression
prefix	the characters from the start of the original sequence to the beginning of the match
suffix	the characters from the end of the match to the end of the original sequence
begin,cbegin	an iterator that enumerates the sub-expressions in *this
end,cend	an iterator that terminates the sub-expressions in *this

Formatting

length	length(int sub=0) 指定子表达式的长度
position	position(int sub=0) 指定子表达式与被匹配串开头之间的字节数
str	str(int sub=0) 指定子表达式匹配得到的字串的长度
operator_at	[]返回子匹配
prefix	原始串的开头到第一个匹配点的字节数
suffix	匹配点的下一个位置到原始串结束的字节数
begin,cbegin	返回指向第一个子匹配(what[0])的迭代器 smatch::iterator iter = what.begin(); ssub_match m1=*iter;
end,cend

format

formats match results for output