#include <iostream>
#include <regex>
#include <string>
 
using   namespace std;
 
struct  FORMATTER
{
	regex   s_rule;
	string  r_rule;
};
 
enum    FORMAT_TYPE
{
	test,
};
 
const   FORMATTER  formats[] =
{
	{ regex( "(\\d{2})(\\d{3})" ), "$1-$2" },
};
 
inline	auto	format( const FORMAT_TYPE type, const int value )
{
    return  regex_replace(
    		to_string( value ), formats[ type ].s_rule, formats[ type ].r_rule );
};
 
int main()
{
   cout << format( test, 12345 ) << endl;
 
   return 0;
}
 

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