there was a somewhat detailed thread (228684) on how to globally (using extern struct) declare a structure that could be seen in more than 1 c++ file, but I can not figure out exactly how to do it (there was a lot of discussion about do this, do that, maybe do this, try this, etc...). couuld someone please post a very simple example of...
I drew a little graph in paint that explains my problem: But it doesn't seem to show up when I use the <img> tag after posting? Here is a direct link: http://i44.tinypic.com/103gcbk.jpg ...
Hi, I am working on a game and have an interesting question. I have some game-wide constant values that I want to implement in one file. Right now I have something like this: constants.cpp extern const int BEGINNING_HEALTH = 10; extern const int BEGINNING_MANA = 5; constants.hpp extern const int BEGINNING_HEALTH; extern const int B...
If you are using a template in C++ that takes an integer value as a parameter, are there any requirements on an integer variable used as the parameter that are different than if the variable was used as a parameter in a function call? This is a follow-up to question here . I specifically want to address if there is a difference WRT v...
I have a dll which comes from a third party, which was written in C++. Here is some information that comes from the dll documentation: //start documentation RECO_DATA{ wchar_t Surname[200]; wchar_t Firstname[200]; } Description: Data structure for receiving the function result. All function result will be stored as Unicode (UTF-8). ...
main.h extern int array[100]; main.c #include "test.h" int array[100] = {0}; int main(void) { /* do_stuff_with_array */ } In the main.c module, the array is defined, and declared. Does the act of also having the extern statement included in the module, cause any problems? I have always visualized the extern statement as...
I just got some C code that uses extern "C" to declare external functions like this: extern "C" void func(); Is this valid C? I'm getting an error at this line, but I'm not sure if it's because of this or something else. ...
I've been getting a compile error in Code::Block for an SDL_Surface variable. Strangely enough, this is the first time I have received this kind of error, as I have used this line of code previously and it has worked fine. One (of several with the same problem) sample line of code that causes this problem is: extern SDL_Surface *screen...
In Unix, I have got three main files. Ones of them as a library and the other one as a program. MyLib.c and MyLic.h are the library. main.c is the program. In MyLic.h I have a declaration (extern int Variable;). When I try to use Variable in main.c I cannot. Of course I have included "MyLib.h" in MyLib.c and in main.c, and I link th...
Consider the following. I have two exported constants as follows: // somefile.h extern const double cMyConstDouble; extern const double cMyConstDouble2; and // somefile.cpp const double cMyConstDouble = 3.14; const double cMyConstDouble2 = 2.5*cMyConstDouble; These constants are now referenced some place else to define two static (...
I'm having trouble with enum visibility in an Objective-C program. I have two header files, and one defines a typedef enum. Another file needs to use the typedef'd type. In straight C, I would simply #include the other header file, but in Objective-C, it's recommended not to use #import between header files, instead using forward @class...
Hi, i develop iPhone apps, and after updating to sdk 3.0, I get an error on CFWriteStreamCreateWithFTPURL while linking. This is the code I call to get the error. streamInfo.writeStream = CFWriteStreamCreateWithFTPURL(NULL, urlRefWrite); I have an idea that it can be solved using extern "C", but after having googled it, I have not fou...
Hello everyone, Just want to confirm in Windows environment, VSTS 2008 + C++ project, we could only apply extern C to function level, not be able to apply to class level (so that all member functions from the class use C language name mangling)? I have tried several ways, but always compile error. thanks in advance, George ...
Hello, Stack Overflow! I was wondering what exactly putting 'extern "C"' in your C++ program does. Thanks! ...
If I have a class in outside.h like: class Outside { public: Outside(int count); GetCount(); } How can I use it in framework.cpp using the extern keyword, where I need to instantiate the class and call GetCount? Edit: #include is not allowed. ...
Simple1.c ------------------------------------ #include"stdio.h" int f1(int x, int y) { printf("%d %d", x, y); return x+y; } ----------------------------------- Simple2.c ------------------------------------ #include"stdio.h" extern int f1(int x,int y); void main() { printf(" %d\n", f1(5,6)); } ----------------------------------- I w...
I am declaring an array of NSString* in a header file of a class. PolygonShape.h NSString* POLYGON_NAMES[] = {@"Invalid Polygon", @"Monogon", ...}; Now I am using this in PolyginShape.m as follows: - (NSString*) name { return (POLYGON_NAMES [self.numberOfSides]); } numberOfSides is an iVar which will indicate the index at which the...
Hi what could be the usage of static and extern pointer ?? if they exist ...
I wrote a C++ function that I need to call from a C program. To make it callable from C, I specified extern "C" on the function declaration. I then compiled the C++ code, but the compiler (Dignus Systems/C++) generated a mangled name for the function. So, it apparently did not honor the extern "C". To resolve this, I added extern "...
I have issue that is reproduced on g++. VC++ doesn't meet any problems. So I have 2 cpp files: 1.cpp: #include <string> #include <iostream> extern const std::string QWERTY; int main() { std::cout << QWERTY.c_str() << std::endl; } 2.cpp: #include <string> const std::string QWERTY("qwerty"); No magic, I just want place string...