text: #include <stdlib.h>
  #include <assert.h>
  #include "bmap.h"
  
  void BMap_clear( BMAP* bm, unsigned int idx )
  {
     unsigned int byte = 0,
                  bit = 0;
     unsigned char mask = 0;
  
     assert( bm != NULL );
     assert( bm->bits != NULL );
  
     byte = idx / ( 8 * sizeof( char ) );
     assert( byte < bm->sizeBytes );
  
     bit = idx % ( 8 * sizeof( char ) );
     assert( bit <= 7 );
     mask = ~( 1 << bit );
  
     bm->bits[ byte ] &= mask;
  }
  