add run time case function

[minamiyama1994]

#define MATCH .template match
auto res = [ ] ( auto x )
{
    case_ ( x )
        MATCH < int > ( [ ] ( int y ) { return y ; } )
        MATCH < double > ( [ ] ( double y ) { return y ; } )
        MATCH < std::vector < pattern < 0 > > > ( [ ] < typename T > ( const std::vector < T > & v ) { return v ; } )
        MATCH < pattern < 0 > > ( [ ] ( auto y ) { return boost::any { y } ; } )
    ;
} ( some_value ) ;

[minamiyama1994]

better solution.

auto res = [ ] ( auto x )
{
    case_ ( x )
        | match < int > ( [ ] ( int y ) { return y ; } )
        | match < double > ( [ ] ( double y ) { return y ; } )
        | match < std::vector < pattern < 0 > > > ( [ ] < typename T > ( const std::vector < T > & v ) { return v ; } )
        | match < pattern < 0 > > ( [ ] ( auto y ) { return boost::any { y } ; } )
    ;
} ( some_value ) ;