C ++ 11 class single_ptr container declared forward

g++ -std=c++11 does not compile a class that contains a container that contains unique pointers that point to a forward declared class. Questions: Why? Is there a reasonable workaround? Code example: #include <vector> #include <memory> // vari

C2027 error: use of undefined type - how to declare a class

I am running into below error - when I just provide the definition of class first and then declare it later. My understanding was as long as we do that as I have done numerous times for function definition, compiler gets it but seems my understanding

structure table declared forward in another structure

I am trying to forward declare a struct A and define a struct B that contains an array of A. I am getting error stating 'incomplete type not allowed' This is what I have: struct A; struct B { // something struct A x[10]; // This where I get the error

How to correctly return a typedef'd structure

What I want to accomplish: I want to use a typedef'd function pointer inside of a typedef'd struct where the function pointer takes a struct pointer as an argument (i.e. something like an 'object method' which takes a self-reference to the 'object').

Forward declaration of the derived internal class

I ran into problem implementing some variations of factory method. // from IFoo.h struct IFoo { struct IBar { virtual ~IBar() = 0; virtual void someMethod() = 0; }; virtual IBar *createBar() = 0; }; // from Foo.h struct Foo : IFoo { // implementation

How to access a private constructor in a separate class?

I'm writing a library in C++. I have two classes in my library, A and B. I want to hide the A() constructor from any code that references my library. I also want class B to be able to call the A() constructor. I come from a C# background and remember

Return type deduction with an explicit prototype in C ++

I've been playing with the return type deduction supported in g++ with -std=c++1y. If you prototype a function with an explicit return type, and then later try to define the function with return type deduction, the compiler complains of an ambiguous

expeditious declaration of procedure in Delphi

How can I make a forward declaration of a procedure in Delphi and make it's implementation in other place? I want to do something like this C's code but in Delphi: void FooBar(); void FooBar() { // Do something } You do that with the forward directiv

transmit reporting problems

I think I am having a problem with forward declarations. I think one is necessary, but I'm not sure. Basically I have a main.cpp: //main.cpp #include <iostream> #include "CalculateForces.h" #include "ParticleBox.h" int main(void)

Forward declaration

I was building an app when I ran into some errors. After doing some research, I found that the reason is because I am working with 2 files, that each #import each other. I read that the cure to this is to use Forward Declaration, but I couldn't find

Inherit from the structure that is declared forward?

Can't I inherit from a structure that was only forward-declared? Example: struct A; class B : public A {}; I am getting the error "base class is undefined". Can you please help me to resolve this issue? ThanksYou can't do so. First of all, when

phase of capturing statement in compilation

languages like C and C++ rely on forward declarations to resolve cyclic dependencies in type or function declarations. In C#, this is not required anymore because the declaration capture phase is split in two phases; one capturing symbol names and a

typedef struct with a forward declaration in C

I have something like: typedef struct Data DATA, *DATA_PTR; typedef struct Units UNITS, *UNITS_PTR; struct Data { double miscData; UNITS units; }; struct Units { double x[2]; double y[2]; double z[2]; }; in my project_typedef.h file. In another file,

Error: 'class name' redeclared as different type of symbol?

I was facing the same error as asked in this question I overcome with this error by solution of declaring class ahead of time in my .h file with the class parameter I am having FFTBufferManager.h and FFTBufferManager.cpp file and using it in HomeView

Forward the statement to include

Consider the following two scenarios (Edited just to complete the whole question and make it clearer) Case 1: (doesnt compile as rightly mentioned below) //B.h #ifndef B_H #define B_H #include "B.h" class A; class B { A obj; public: void printA_

Forward C ++ declaration and pure virtual functions

I have a problem using forward declaration and virtual functions. I got the following error message during compilation. main.cpp:131: error: cannot allocate an object of abstract type 'Database::MySQL' database_mysql.h:31: note: because the following

C ++ boost advanced reporting question

I spend some time examining boost:: libraries architecture and was interested with the following fact: In some parts of the libraries a yyy_fwd.hpp idea is used pretty common (see boost/detail or boost/flyweight for examples). These files obviously c

How can I transmit an internal class?

Possible Duplicate: Forward declaration of nested types/classes in C++ I have a class like so... class Container { public: class Iterator { ... }; ... }; Elsewhere, I want to pass a Container::Iterator by reference, but I don't want to include the he

Alternative to advance returns when you do not want to #include

I usually, almost without thinking anymore, use forward declarations so that I won't have to include headers. Something along this example: //----------------------- // foo.h //----------------------- class foo { foo(); ~foo(); }; //-----------------