Unlike a named class or struct, unnamed classes and structs must be instantiated where they are defined, and cannot have constructors or destructors.
struct {
int foo;
double bar;
} foobar;
foobar.foo = 5;
foobar.bar = 4.0;
class {
int baz;
public:
int buzz;
void setBaz(int v) {
baz = v;
}
} barbar;
barbar.setBaz(15);
barbar.buzz = 2;