Move the typedef struct Preprocessor Prepro; to the header the file and the definition in the c file along with the Prepro_init definition. This is will forward declare it for you with no issues. Preprocessor.h #ifndef _PREPROCESSOR_H_ #define _PREPROCESSOR_H_ #define MAX_FILES 15 typedef struct Preprocessor Prepro; void Prepro_init(Prepro* p); #endif Preprocessor.c #include “Preprocessor.h” #include <stdio.h> … Read more
Lua is a dynamic language and functions are just a kind of value that can be called with the () operator. So you don’t really need to forward declare the function so much as make sure that the variable in scope when you call it is the variable you think it is. This is not … Read more
Use forward declaration when possible. Suppose you want to define a new class B that uses objects of class A. B only uses references or pointers to A. Use forward declaration then you don’t need to include <A.h>. This will in turn speed a little bit the compilation. class A ; class B { private: … Read more
It sounds like these classes are fairly common to much of your project. You might try some of these: Do your best to break apart ProjectForwards.h into several files as you suggested. Make sure each subsystem only gets the declarations it truly needs. If nothing else, that process will force you to think about the … Read more
Firefox interprets function statements differently and apparently they broke declaration hoisting for the function declaration. ( A good read about named functions / declaration vs expression ) Why does Firefox interpret statements differently is because of the following code: if ( true ) { function test(){alert(“YAY”);} } else { function test(){alert(“FAIL”);} } test(); // should … Read more
struct and class are completely interchangeable as far as forward declarations are concerned. Even for definitions, they only affect the default access specifier of the objects members, everything else is equivalent. You always define “classes” of objects. The only place where struct must be used over class, is when forward declaring opaque data for c … Read more
Well, apart from the issues about duplication… … there is at least one sore spot in the Standard. If you call delete on a pointer to an incomplete type, you get undefined behavior. In practice, the destructor may not get called. We can see that on LiveWorkSpace using the following command and sample: // -std=c++11 … Read more
You can’t forward-declare a nested class like that. Depending on what you’re trying to do, maybe you can use a namespace rather than a class on the outer layer. You can forward-declare such a class no problem: namespace Outer { struct Inner; }; Outer::Inner* sweets; // Outer::Inner is incomplete so // I can only make … Read more
This form of function definition: void fun(int i; int i) { } uses a GNU C extension called the parameter forward declaration feature. http://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html This feature allows you to have parameter forward declarations before the actual list of parameters. This can be used for example for functions with variable length array parameters to declare a … Read more
It’s so you can declare, in your own headers, methods that rely on the declarations of iostream types without having to #include the iostream headers themselves, which are large, complex and slow to compile against. Here’s a simple example: // foo.h #include <iosfwd> void sucker(std::iostream& is); // foo.cc #include <iostream> void sucker(std::iostream& is) { … Read more