Looking Up Definitions of Types and Classes

The -t option of the whatis command displays the definition of a type. For C++, the list displayed by whatis -t includes template definitions and class template instantiations.

To print the declaration of a type or C++ class:

(dbx) whatis -t type-orclassname

To see inherited members, the whatis command takes an -r option (for recursive) that displays the declaration of a specified class together with the members it inherits from base classes.

(dbx) whatis -t -r  class-name

The output from a whatis -r query might be long, depending on the class hierarchy and the size of the classes. The output begins with the list of members inherited from the most ancestral class. The inserted comment lines separate the list of members into their respective parent classes.

To see the root of a class's inherited members, the whatis command takes a -u option that displays the root of the type definition. Without the -u option, the whatis command will display the last value in the value history. This is similar to the ptype command used in gdb.

The following two examples us the class table, a child class of the parent class load_bearing_block, which is, in turn, a child class of block.

Without -r, whatis reports the members declared in class table.

(dbx) whatis -t class table
class table : public load_bearing_block {
public:
    table::table(char *name, int w, int h, const class point &pos);
    virtual char *table::type();
    virtual void table::draw(unsigned long pw);
};

Te following examples show the results when whatis -r is used on a child class to see members it inherits.

(dbx) whatis -t -r class table
class table : public load_bearing_block {
public:
  /* from base class table::load_bearing_block::block */
  block::block();
  block::block(char *name, int w, int h, const class point &pos, class load_bearing_block *blk);
    virtual char *block::type();
    char *block::name();
    int block::is_movable();
//  deleted several members from example protected:
    char *nm;
    int movable;
    int width;
    int height;
    class point  position;
    class load_bearing_block *supported_by;
    Panel_item panel_item;
    /* from base class table::load_bearing_block */
public:
    load_bearing_block::load_bearing_block();
    load_bearing_block::load_bearing_block(char *name, int w, int h,
        const class point &pos, class load_bearing_block *blk);
    virtual int load_bearing_block::is_load_bearing();
    virtual class list *load_bearing_block::supported_blocks();
    void load_bearing_block::add_supported_block(class block &b);
    void load_bearing_block::remove_supported_block(class block &b);
    virtual void load_bearing_block::print_supported_blocks();
    virtual void load_bearing_block::clear_top();
    virtual void load_bearing_block::put_on(class block &object);
    class point load_bearing_block::get_space(class block &object);
    class point load_bearing_block::find_space(class block &object);
    class point load_bearing_block::make_space(class block &object);
protected:
    class list *support_for;
    /* from class table */
public:
    table::table(char *name, int w, int h, const class point &pos);
    virtual char *table::type();
    virtual void table::draw(unsigned long pw);
};