[re.regex.operations] # 28 Text processing library [[text]](./#text) ## 28.6 Regular expressions library [[re]](re#regex.operations) ### 28.6.7 Class template basic_regex [[re.regex]](re.regex#operations) #### 28.6.7.4 Constant operations [re.regex.operations] [🔗](#lib:mark_count,basic_regex) `unsigned mark_count() const; ` [1](#1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L10744) *Effects*: Returns the number of marked sub-expressions within the regular expression[.](#1.sentence-1) [🔗](#lib:flag_type,basic_regex) `flag_type flags() const; ` [2](#2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/text.tex#L10756) *Effects*: Returns a copy of the regular expression syntax flags that were passed to the object's constructor or to the last call to assign[.](#2.sentence-1)