“The only difference between a struct and a class is in the default access.”

That is, a sruct is public by default and a class is private by default. Extending (inheriting) them is also like-wise – public inheritance for struct and private for class.

I believe struct was made public by default to be compliant with C . Thus a C struct can be used similarly in C++. i.e.

[cpp]

struct Foo
{
int bar;
char* baz;
};

Foo makeFoo()
{
Foo temp;
temp.bar = 1;
temp.baz = “test”;
return temp;
}

[/cpp]

The only reason the above code will work in C++ is because of the default access of struct being public.