C++ :: Forward Declaration Of Vector In Header File
Nov 7, 2014
I have a header file in which we include vector at the top. But we want to remove that include. On doing so I get compilation errors as the header file uses std::vector<> at several instances in header file so I have to forward declare the vector to solve this issue.how i can do it.
I am using OpenCASCADE environment to read STL file! I face a problem, with forward declaration error with the following
void StlReadIn::STL_Import() { std::string FileName; std::cout<<" Enter the file name "; std::cin>>FileName;
[Code] .....
Error message:
stlreadin.cpp:26:47: error: invalid use of incomplete type ‘struct StlMesh_Mesh’ /usr/local/oce-0.9.1/include/oce/Handle_StlMesh_Mesh.hxx:23:7: error: forward declaration of ‘struct StlMesh_Mesh’
I have a class "SelectionGroup" which derives from a class "RMFObjectContainer". RMFObjectContainer has member variables of type SelectionGroup, so I need to include SelectionGroup.h in the header of RMFObjectContainer.h.
However, since SelectionGroup needs RMFObjectContainer to derive from it, I get a typical case of mutual inclusion.
I then proceeded to put the forward declaration class RMFObjectContainer; instead of #include "RMFObjectContainer.h" into the header of SelectionGroup.h.
However, I receive the following compile error (MSVC2010), as if the forward declaration was unseen:
#pragma once #include "Solid.h" #include "Entity.h" #include "SelectionGroup.h"
Code: class SomeOtherClass; void foo(SomeOtherClass* p);
And
Code: void foo(class SomeOtherClass* p);
I was told that "2" would limit the scope of the forward declaration to the declaration of foo... However, after testing it, it appears that both behave the same...
I am trying to compile the files below. The PosLin.cpp contains the SurTriAuto and SurTriPosRotAndQ functions below. Before adding SurTriPosRotAndQ, it compiled fine, but when I added SurTriPosRotAndQ, I am getting "invalid use of incomplete type ‘struct PosRotAndQ" error messages
I was thinking I could try moving SurTriAuto and SurTriPosRotAndQ to PosLin.h, but since they return "T*", I'm not sure what to do
I have a "t.h" file
namespace TNS { class T {
[Code]....
when I add "include Pos/PL.h" to geopar.h, I get an error saying v.hpp is missing, where v.hpp is part of a 3rd-party software and it is already in my directory
I'm working on a grocery store inventory project. One part is to have a shopping cart, where customers can put in up to 20 items. Because there can be up to 20 shopping carts at one time, I want to use a vector inside the cart object to represent all the individual food items.
Here's my code,
Header:
#ifndef CART_H #define CART_H #include <vector> class Cart { public: Cart(); Cart(std::vector< int >, std::vector< int >)
I was going through a code where i found the definition of int array[63] in one of the source files. But i also found the declaration as extern int array[66] in another source file. This is clearly wrong, but my doubt is how the compiler compiled it. It should have thrown error. In case if it compiles then what will be the behavior of the system? Will it be normal or some undefined behavior?
I have a cpp app that reads in a number of files and writes revised output. The app doesn't seem to be able to open a file with a ' in the file name, such as,
N,N'-dimethylethylenediamine.mol
This is the function that opens the file :
Code: // opens mol file, reads in rows to string vector and returns vector vector<string> get_mol_file(string& filePath) { vector<string> mol_file; string new_mol_line; // create an input stream and open the mol file ifstream read_mol_input; read_mol_input.open( filePath.c_str() );
[Code] ....
The path to the file is passed as a cpp string and the c version is used to open the file. Do I need to handle this as a special case? It is possible that there could be " as well, parenthesis, etc.
I have written my program and it works when I keep everything in the header files, and then have my main. I am now splitting them up into implementation files, but Eclipse keeps giving me errors. It gives me error at every opening brace of the constructor and functions. It says on all of them "Redefinition of (name of constructor or method), Previously declared here." What am I doing wrong, because it works in the header file?
I wanted to share the value of a variable from Sender Program to Receive after program and want to calculate difference between send and receive. After studying Header file concept I program following three.
Now I am struck. How to to compile? I link all these file. I used following method:
Then I run Sender and after that Receiver.I per my knowledge, Receiver should give difference but it gives error :
Code: Receiver.c: In function "main": Receiver.c:10:42: error: "Send" undeclared (first use in this function) printf(" Total Receive is %d ",Receive-Send);
Code: Sender.c #include <stdio.h> int Send ; void main(){
I have been working a project in C++. I have TTTMain.cpp file that has all the function calls, TTTFuntions.cpp that has all the functions, I have TTT.h file that has all the prototypes and variables and additionally I have Winner.h that has enum class Winner declaration in it. Here is my block of codes:
Winner.h file:
#ifndef winner #define winner enum class Winner {
[Code]....
My question is when I compile this gives me error on
I made my header file. If cpp file with definitions is in project compiler knows it has to be linked, but if it's not compiler doesn't know. If I include standard library or boost I don't have to manually link cpps. How to do so including my header automatically links cpp? Maybe problem is with something else?I use VS 2013.
My socket.cpp program got error. it showed "socket.h: no such file or directory". I had put my header file (socket.h) in the same place with my source file.
1. Write a program the calculates the volume of a sphere.
Use a define to set Pi to 3.14 and a macro for the formula for the sphere. V = 4/3PiR3. In main ask for the radius (R). Pass it to a function where you calculate the volume and return it to main and print the volume in main. Use float values. (Save this program as you'll need it later.)
I have a class Myclass (for the sake of the example). I have a header file 'space.h', which is following:
#include "Myclass.h" struct Files {Myclass* new_object, int number};
But turns out in the Myclass.h, I need the struct Files, like so:void function(vector<Files> arrangement);
So I would have to include "space.h" in the Myclass.h, but this way there's going to be a double definition of struct Files, since Myclass.h includes space.h and space.h includes Myclass.h.
