value?

/*
 *  call-seq:
 *     hsh.has_value?(value)    => true or false
 *     hsh.value?(value)        => true or false
 *  
 *  Returns <code>true</code> if the given value is present for some key
 *  in <i>hsh</i>.
 *     
 *     h = { "a" => 100, "b" => 200 }
 *     h.has_value?(100)   #=> true
 *     h.has_value?(999)   #=> false
 */

static VALUE
rb_hash_has_value(hash, val)
    VALUE hash;
    VALUE val;
{
    VALUE data[2];

    data[0] = Qfalse;
    data[1] = val;
    rb_hash_foreach(hash, rb_hash_search_value, (st_data_t)data);
    return data[0];
}