Irrlicht Engine

class saving
{
f32 a1;
u32 a2;
const wchar_t* a3;

public:
saving()
{a1 = 2.0;a2 = 3;a3 = L"abc";}

void save()
{
a1 = 4;
a2 = 6;
a3 = L"abcde";
IWriteFile *fwrite = device->getFileSystem()->createAndWriteFile("aaa.ini", true);
fwrite->write(reinterpret_cast<char *>(this), sizeof(this));
fwrite->drop();
}

void load()
{
IReadFile *fast = device->getFileSystem()->createAndOpenFile("Optsdion.ini");
fast->read(reinterpret_cast<char *>(this), sizeof(this));
fast->drop();
}
void show()
{
std::cout<<a1<<"\n";
std::cout<<a2<<"\n";
std::wcout<<a3<<"\n";
}}s;


i called upon

s.save(); //for saving object
//s.load()
//s.show()

now when the file wz saved then i used

//s.save()
s.load();
s.show();

here the output screen showed me

4
3
abc

only first value is loaded correctly and the rest two , i don't know why they r not loaded.
r they saved or not plz help and if so why they r not on the output screen as the output should be 4 6 abcde

sorry i have miswritten in early post

IReadFile *fast = device->getFileSystem()->createAndOpenFile("aaa.ini");

now i changed the code a little bit and changed to

fwrite->write(reinterpret_cast<char *>(this), sizeof(saving));
fwrite->read(reinterpret_cast<char *>(this), sizeof(saving));
now it is showing first two variable correctly but it is not writing the wchar
srting. How can i write wchar string to the file

Havent tried, but think sizeof(this) doesnt include the length of a3, just the size of the pointer (that should be sizeof(int) ).

You should use something like sizeof(this) + length( a3 ).

That's right, Warchief. And furthermore only the pointer is written to the file, because technically only the wchar_t is member of the saving class. the actual string is somewhere in the data segment of this module.

There is no flexible way, to just put a variable length data block (like a string) into a file this way. Your save function has to take care of such data explicitly. For instance, if you write a string. First write the length of it, then read the next length characters into a newly created zero filled buffer of length+1 (0 terminated strings) and put the pointer to this buffer to your a3. Proceed accordingly to save it.
Frankly, I'd not use the IRead/WriteFile interface for this. It is simple, but not very comfortable. std::iostream is much more comfortable, especially using filters, but one needs to get accustomed to it. Worth to take a look at it.

i think u should prefer XML parser for ur saving and loading which is i think more efficiant although binary is more faster but i prefer XML.