common.h

#pragma once
#include <iostream>

//----------------------------------------------------------------
inline
bool operator>>=( std::istream& input, const char c )
{
	if( input.peek() != c )
		return false;

	input.ignore();
	return true;
}
bool operator>>=( std::istream& input, const char* s );

//----------------------------------------------------------------
std::istream& operator>>( std::istream& input, const char c );
std::istream& operator>>( std::istream& input, const char* s );

//================================================================
static class Any_line {} any_line;
inline std::istream& operator>>( std::istream& input, Any_line s )
{
	//if( !input )
	//	return input;
	input.ignore( INT_MAX, '\n' );
		return input;
}
inline std::ostream& operator<<( std::ostream& output, Any_line s )
{
	output << '\n';
	return output;
}

//================================================================
static class Any_word {} any_word;
inline std::istream& operator>>( std::istream& input, Any_word s )
{
	if( !input )
		return input;
	char c;
	while( input.get( c))
	{
		if( !isgraph( c ) )
			break;
	}
	input.unget();
	return input;
}
inline std::ostream& operator<<( std::ostream& output, Any_word s )
{
	output << 'X';
	return output;
}

//================================================================
class Digit_char
{
public:
	char value;

	Digit_char(			) : value(  '\0') {};
	Digit_char( const char c	) : value( c-'0') {};

	bool mayread( std::istream& input )
	{
		int c = input.peek() - '0';
		if( c < 0 || c > 9 )
			return false;

		value = c;
		input.ignore();
		return true;
	};

	void read( std::istream& input )
	{
		//if( !input )
		//	return;

		int c = input.peek() - '0';
		if( 0 <= c && c <= 9 )
		{
			value = c;
			input.ignore();
			return;
		}
		std::cerr << "Wrong read! Char: \"" << char( c + '0' ) << "\" not is digit";
	        input.setstate( std::ios_base::failbit );
	};
	void print( std::ostream& output ) const { output << (value + '0'); };
};

//----------------------------------------------------------------
inline bool		operator>>=( std::istream& input,	Digit_char &value) { return value.mayread( input );		}
inline std::istream&	operator>> ( std::istream& input,	Digit_char &value) { value.read( input );	return input;	}
inline std::ostream&	operator<< ( std::ostream& output, const Digit_char value) { value.print( output );	return output;	}