Hex Editor Neo Neo requires that each referenced type must be defined before it is used; otherwise, the compile-time error occurs. Sometimes it is impossible or inconvenient to follow this rule. Forward declarations allow you to declare the identifier as a user-defined type, without actually defining it:
struct B; // forward declaration of B
struct A
{
B b; // compiles OK, as B has been declared
};
struct B // actually define B
{
// …
};
Syntax:
(struct | union | case_union) name-id ;
name-id
is required in forward declarations.
All forward declarations must be resolved before the end of the source file, otherwise an error occurs. However, it is not an error not to resolve a forward declaration if it has not been referenced.