#define rb_obj_initialize rb_obj_dummy0

Returns a newBasicObject.

VALUErb_obj_not(VALUE obj){    return RBOOL(!RTEST(obj));}

Boolean negate.

VALUErb_obj_not_equal(VALUE obj1, VALUE obj2){    VALUE result = rb_funcall(obj1, id_eq, 1, obj2);    return rb_obj_not(result);}

Returns true if two objects are not-equal, otherwise false.

VALUErb_obj_equal(VALUE obj1, VALUE obj2){    return RBOOL(obj1 == obj2);}

Equality — At theObject level,== returnstrue only ifobj andother are the same object. Typically, this method is overridden in descendant classes to provide class-specific meaning.

Unlike==, theequal? method should never be overridden by subclasses as it is used to determine object identity (that is,a.equal?(b) if and only ifa is the same object asb):

obj ="a"other =obj.dupobj==other#=> trueobj.equal?other#=> falseobj.equal?obj#=> true

The eql? method returnstrue ifobj andother refer to the same hash key. This is used byHash to test members for equality. For any pair of objects where eql? returnstrue, the hash value of both objects must be equal. So any subclass that overrides eql? should also override hash appropriately.

For objects of classObject, eql? is synonymous with==. Subclasses normally continue this tradition by aliasing eql? to their overridden== method, but there are exceptions.Numeric types, for example, perform type conversion across==, but not across eql?, so:

1==1.0#=> true1.eql?1.0#=> false

VALUErb_obj_id(VALUE obj){    /* If obj is an immediate, the object ID is obj directly converted to a Numeric.     * Otherwise, the object ID is a Numeric that is a non-zero multiple of     * (RUBY_IMMEDIATE_MASK + 1) which guarantees that it does not collide with     * any immediates. */    return rb_find_object_id(rb_gc_get_objspace(), obj, object_id);}

Returns an integer identifier forobj.

The same number will be returned on all calls toobject_id for a given object, and no two active objects will share an id.

Note: that some objects of builtin classes are reused for optimization. This is the case for immediate values and frozen string literals.

BasicObject implements__id__,Kernel implementsobject_id.

Immediate values are not passed by reference but are passed by value:nil,true,false, Fixnums, Symbols, and some Floats.

Object.new.object_id==Object.new.object_id# => false(21*2).object_id== (21*2).object_id# => true"hello".object_id=="hello".object_id# => false"hi".freeze.object_id=="hi".freeze.object_id# => true

VALUErb_f_send(int argc, VALUE *argv, VALUE recv){    return send_internal_kw(argc, argv, recv, CALL_FCALL);}

Invokes the method identified bysymbol, passing it any arguments specified. When the method is identified by a string, the string is converted to a symbol.

BasicObject implements__send__,Kernel implementssend.__send__ is safer thansend whenobj has the same method name likeSocket. See alsopublic_send.

classKlassdefhello(*args)"Hello "+args.join(' ')endendk =Klass.newk.send:hello,"gentle","readers"#=> "Hello gentle readers"

Equality — At theObject level,== returnstrue only ifobj andother are the same object. Typically, this method is overridden in descendant classes to provide class-specific meaning.

Unlike==, theequal? method should never be overridden by subclasses as it is used to determine object identity (that is,a.equal?(b) if and only ifa is the same object asb):

obj ="a"other =obj.dupobj==other#=> trueobj.equal?other#=> falseobj.equal?obj#=> true

The eql? method returnstrue ifobj andother refer to the same hash key. This is used byHash to test members for equality. For any pair of objects where eql? returnstrue, the hash value of both objects must be equal. So any subclass that overrides eql? should also override hash appropriately.

For objects of classObject, eql? is synonymous with==. Subclasses normally continue this tradition by aliasing eql? to their overridden== method, but there are exceptions.Numeric types, for example, perform type conversion across==, but not across eql?, so:

1==1.0#=> true1.eql?1.0#=> false

static VALUErb_obj_instance_eval_internal(int argc, const VALUE *argv, VALUE self){    return specific_eval(argc, argv, self, TRUE, RB_PASS_CALLED_KEYWORDS);}

Evaluates a string containing Ruby source code, or the given block, within the context of the receiver (obj). In order to set the context, the variableself is set toobj while the code is executing, giving the code access toobj’s instance variables and private methods.

Wheninstance_eval is given a block,obj is also passed in as the block’s only argument.

Wheninstance_eval is given aString, the optional second and third parameters supply a filename and starting line number that are used when reporting compilation errors.

classKlassWithSecretdefinitialize@secret =99endprivatedefthe_secret"Ssssh! The secret is #{@secret}."endendk =KlassWithSecret.newk.instance_eval {@secret }#=> 99k.instance_eval {the_secret }#=> "Ssssh! The secret is 99."k.instance_eval {|obj|obj==self }#=> true

static VALUErb_obj_instance_exec_internal(int argc, const VALUE *argv, VALUE self){    return yield_under(self, TRUE, argc, argv, RB_PASS_CALLED_KEYWORDS);}

Executes the given block within the context of the receiver (obj). In order to set the context, the variableself is set toobj while the code is executing, giving the code access toobj’s instance variables. Arguments are passed as block parameters.

classKlassWithSecretdefinitialize@secret =99endendk =KlassWithSecret.newk.instance_exec(5) {|x|@secret+x }#=> 104

static VALUErb_method_missing(int argc, const VALUE *argv, VALUE obj){    rb_execution_context_t *ec = GET_EC();    raise_method_missing(ec, argc, argv, obj, ec->method_missing_reason);    UNREACHABLE_RETURN(Qnil);}

Invoked by Ruby whenobj is sent a message it cannot handle.symbol is the symbol for the method called, andargs are any arguments that were passed to it. By default, the interpreter raises an error when this method is called. However, it is possible to override the method to provide more dynamic behavior. If it is decided that a particular method should not be handled, thensuper should be called, so that ancestors can pick up the missing method. The example below creates a classRoman, which responds to methods with names consisting of roman numerals, returning the corresponding integer values.

classRomandefroman_to_int(str)# ...enddefmethod_missing(symbol,*args)str =symbol.id2namebeginroman_to_int(str)rescuesuper(symbol,*args)endendendr =Roman.newr.iv#=> 4r.xxiii#=> 23r.mm#=> 2000r.foo#=> NoMethodError

#define rb_obj_singleton_method_added rb_obj_dummy1

Invoked as a callback whenever a singleton method is added to the receiver.

moduleChattydefChatty.singleton_method_added(id)puts"Adding #{id.id2name}"enddefself.one()enddeftwo()enddefChatty.three()endend

produces:

Addingsingleton_method_addedAddingoneAddingthree

#define rb_obj_singleton_method_removed rb_obj_dummy1

Invoked as a callback whenever a singleton method is removed from the receiver.

moduleChattydefChatty.singleton_method_removed(id)puts"Removing #{id.id2name}"enddefself.one()enddeftwo()enddefChatty.three()endclass<<selfremove_method:threeremove_method:oneendend

produces:

RemovingthreeRemovingone

#define rb_obj_singleton_method_undefined rb_obj_dummy1

Invoked as a callback whenever a singleton method is undefined in the receiver.

moduleChattydefChatty.singleton_method_undefined(id)puts"Undefining #{id.id2name}"enddefChatty.one()endclass<<selfundef_method(:one)endend

produces:

Undefiningone