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            The matches[]
            directive executes the embedded parser and returns whether it succeeded
            matching.
          
// forwards to <boost/spirit/home/qi/directive/matches.hpp> #include <boost/spirit/include/qi_matches.hpp>
Also, see Include Structure.
| Name | 
|---|
| 
                       | 
Notation
a
                  A Parser.
                
            Semantics of an expression is defined only where it differs from, or
            is not defined in UnaryParser.
          
| Expression | Semantics | 
|---|---|
| 
                       | 
                      Execute the subject parser  | 
| Expression | Attribute | 
|---|---|
| 
                       | 
                       | 
The complexity is defined by the complexity of the subject parser,
a
| ![[Note]](../../../../images/note.png) | Note | 
|---|---|
| The test harness for the example(s) below is presented in the Basics Examples section. | 
Some using declarations:
using boost::spirit::qi::matches; using boost::spirit::qi::int_;
            This parser tries to match an int
            and returns true a its attribute
            as it succeeded matching:
          
bool result = false; test_parser_attr("345", matches[int_], result); std::cout << std::boolalpha << result << std::endl; // should print: true
            This parser tries to match an int
            as well and returns false
            as its attribute as it fails matching:
          
result = true; test_parser_attr("abc", matches[int_], result); std::cout << std::boolalpha << result << std::endl; // should print: false