Revision 34 Version 14

 Now M2000 can use object arrays (4 byte per item, pointer to object - any object) to hold at the end a buffer object which is an array of memory items (in a flat manner). Although if we use string as item we get 4 bytes for a pointer to a BSTR string. So when we use these strings we don't serialize the structure easy (as flat memory) (if we get the string representation of a buffer we get zero for BSTR pointers, unless we do some actions on data, like to write to StrPtr, M2000 keep truck of actuall strings, so the pointer on the buffer for bstr is just a copy, but if the we change the copy M2000 return dummy string "crash" without crashing)

Easy Example:

structure simple {
	x as double
	y as double
	{ StrPtr as long} ' we make a union
	name1 as string
}
simple one[5], zero
zero|name1="This is a BSTR string"
Print len(Simple)=20 ' 20 bytes, 2x8 bytes double, 4 bytes pointer to string
one[3]=zero ' copy to one at index 3 (4th item)
Print len(zero)=20, len(one)=20*5  ' 20 bytes and 100bytes
print Len(one[3]|name1)=21 ' characters = 21 words = 21*2 bytes
print one[3]|StrPtr  ' this is the address of the string
print one[0]|StrPtr=0  ' this is null string
print Len(one[0]|name1)=0
' now start the real example
Object alfa[3], beta[3][2]
alfa[1]=one
print alfa[1][3]|name1="This is a BSTR string"
print alfa[1] is one, " : True"  ' we have the same object
alfa[2]=buffer(one)  ' we get a copy of all items
alfa[3]=one[3] ' using one[3] we get a copy of item 3
print alfa[2] is one, " : False"  ' we have different objects
print alfa[2][3]|name1
print alfa[1][3]|StrPtr=one[3]|StrPtr, " : True"
print alfa[2][3]|StrPtr=one[3]|StrPtr, " : False"
print len(alfa[3])=20  ' one only item
print alfa[3]|name1="This is a BSTR string"
print alfa[3]|StrPtr=one[3]|StrPtr, " : False"
beta[3][0]=one
print beta[3][0] is alfa[1], " : True"
beta[3][0][3]|name1="New string"
print alfa[1][3]|name1="New string", " : True"
print one[3]|name1="New string", " : True"
' we can put an object in an array of objects too
beta[3][2]=alfa
print beta[3][2][1][3]|name1="New string", " : True"
zero=beta[3][2][1][3]  'we get the index 3 of object at beta[3][2][1]
' zero is a copy 
print zero|name1="New string", " : True"
print zero|StrPtr<>beta[3][2][1][3]|StrPtr, " : True"
zero=beta[3][2][1]
zero[3]|name1="last string"
' zero now point to beta[3][2][1]
print zero is one, " : True"
print zero is alfa[1], " : True"
print zero is beta[3][2][1], " : True"
print zero is beta[3][0], " : True"
print beta[3][0][3]|name1="last string", " : True"

Haed Example:

structure simple {
	x as double
	y as double
	{StrPtr as long} ' we make a union
	name1 as string
}
structure bigone {
	{simple};   ' import simple (using ; we bypass the uninon mechanism)
	z as double * 100
}
structure bigtwo {
	s as simple * 4
	z as double * 10
}
bigtwo two[10]
bigone one[5]
simple zero
zero|name1="This is a BSTR string"
print len(Simple)=20 ' 20 bytes, 2x8 bytes double, 4 bytes pointer to string
one[3]=zero 
print len(zero)=20, len(one)=(20+100*8)*5  ' 20 bytes and 100bytes
print one[3]|name1=zero|name1, one[3]|StrPtr<>zero|StrPtr 
print Len(two)=(4*20+10*8)*10
two[2]|s[1]=zero
print two[2]|s[1]|name1=zero|name1, two[2]|s[1]|StrPtr<>zero|StrPtr 
two[2]|s[1]|name1="new string"
print two[2]|s[1]|name1=zero|name1, " : False"
zero=two[2]|s[1]  ' get a copy
print two[2]|s[1]|name1=zero|name1, two[2]|s[1]|StrPtr<>zero|StrPtr 
' now the real example
Object alfa[4], beta[3][2]
alfa[2]=two
print alfa[2][2]|s[1]|name1=zero|name1
beta[3][1]=one
print beta[3][1][3]|name1="This is a BSTR string"
beta[3][1][3]=zero  ' copy because ...[3] is index to buffer at beta[3][1]
print type$(beta[3][1])="Buffer"
print beta[3][1][3]|name1=zero|name1
print_name1(beta[3][1][3])
print_name2(zero) ' zero is object pass pointer
print zero|name1, zero|StrPtr ' we get new values.
print alfa[2][2]|s[1]|name1, alfa[2][2]|s[1]|StrPtr,  " values before call"
print_name2(alfa[2][2]|s[1])  ' pass copy
print alfa[2][2]|s[1]|name1, alfa[2][2]|s[1]|StrPtr,  " same values as before call"
print_name3(alfa[2],2,1) ' alfa[2] is object - pass pointer
print alfa[2][2]|s[1]|name1, "change name"
sub print_name1(a as bigone)
	print a|name1, a|StrPtr, a|z[30], " inside print_name1()"
end sub
sub print_name2(a as simple)
	print a|name1, a|StrPtr, " inside print_name2()"
	a|name1=a|name1+"...ok...."
end sub
sub print_name3(a as bigtwo, index, n)
	print a[index]|s[n]|name1, a[index]|s[n]|StrPtr, " inside print_name3()"
	a[index]|s[n]|name1=a[index]|s[n]|name1+"...ok"
end sub