#include <stddef.h>
#include <stdbool.h>
#include <stdio.h>

void call_for_each( void (*fun)( int ), int start, int end )
{
	for( int i = start; i < end; i++ )
		fun( i );
}

bool contains( int const values[], size_t count, int match )
{
	__label__ found;

	// note: only supported by gcc, not by g++ or clang
	void check( int index ) {
		if( values[ index ] == match )
			goto found;
	}

	call_for_each( check, 0, count );
	return false;
found:
	return true;
}

int main()
{
	int const values[] = { 2, 5, 7 };
	size_t const count = sizeof(values) / sizeof(int);

	for( int i = 0; i < 8; i++ ) {
		printf( "contains %d: %s\n", i,
			contains( values, count, i ) ? "yes" : "no" );
	}

	return 0;
}