header-files

C++: Is windows.h generally an efficient code library?

I heard some people complaining about including the windows header file in a C++ application and using it. They mentioned that it is inefficient. Is this just some urban legend or are there really some real hard facts behind it? In other words, if you believe it is efficient or inefficient please explain how this can be with facts. I a...

Should '#include' and 'using' statements be repeated in both header and implementation files (C++)?

I'm fairly new to C++, but my understanding is that a #include statement will essentially just dump the contents of the #included file into the location of that statement. This means that if I have a number of '#include' and 'using' statements in my header file, my implementation file can just #include the header file, and the compiler w...

How to keep g++ from taking header file from /usr/include?

I am building using zlib.h which I have a local copy to v1.2.5, but in /usr/include/zlib.h there is v1.2.1.2. If I omit adding -I/my/path/to/zlib to my make I get error from using old version which doesn't have Z_FIXED: g++ -g -Werror -Wredundant-decls -D_FILE_OFFSET_BITS=64 -c -o ARCH.linux_26_i86/debug/sysParam.o sysParam.cpp sysPara...

multiple definition in header file

Here is a small code-example from which I'd like to ask a question : complex.h : #ifndef COMPLEX_H #define COMPLEX_H #include <iostream> class Complex { public: Complex(float Real, float Imaginary); float real() const { return m_Real; }; private: friend std::ostream& operator<<(std::ostream& o, const Complex& Cplx); fl...

Declaring struct in header file

I've been trying to include a structure called "student" in a student.h file, but I'm not quite sure how to do it. My student.h file code consists of entirely: #include<string> using namespace std; struct Student; while the student.cpp file consists of entirely: #include<string> using namespace std; struct Student { string las...

osx sys/io.h not found

Hi, I'd like to compile a c programm developed for linux using cc under os x. It includes the header sys/io.h. When compiling I get the error that this file could not be found? Isn't there any sys/io.h header file under os x? Any help would be really appreciated! Thanks! ...

XCode can't find headers in /usr/include

Hi all, I'm trying to use standard system header files in my C++ XCode project: #include <openssl/bio.h> #include <openssl/ssl.h> #include <openssl/err.h> The build fails and it complains: "Openssl/bio.h: No such file or directory" I added /usr/include to the "Header Search Paths" in Project settings, but that doesn't fix it. I CO...

About using assembly with c

Hi. I've sort of just finished a mandatory task at school, and I'm about to deliver it. But then I came across something that was unfamiliar, header files. :( What I've got: test-program.c task_header.h function1.s function2.s function3.s function4.s test-program.c: #include <stdio.h> #include <stdlib.h> #include <string.h> #incl...

C++ Beginner - Trouble using classes inside of classes

Hello, I am working on a college project, where I have to implement a simple Scrabble game. I have a player class (containing a Score and the player's hand, in the form of a std::string, and a score class (containing a name and numeric (int) score). One of Player's member-functions is Score getScore(), which returns a Score object for...

How can I create C header files.

I want to be able to create a collection of functions in a header file that I could #include in one of my C Programs. ...

Header files inclusion / Forward declaration

Hi, In my C++ project when I have to go for the inclusion (#include "myclass.h") of header files?? And when I have to go for forward declaration of the class (class CMyClass;) ?? Any suggestions regarding this are welcome. ...

Have xcode search regular include paths before my HEADER_SEARCH_PATHS

I need to force xcode/gcc to search the default system header search paths BEFORE searching my project HEADER_SEARCH_PATHS. Any idea how I can accomplish this? ...

Use the keyword class as a variable name in C++

I am having trouble writing C++ code that uses a header file designed for a C file. In particular, the header file used a variable name called class: int BPY_class_validate(const char *class_type, PyObject *class, PyObject *base_class, BPY_class_attr_check* class_attrs, PyObject **py_class_attrs); This works in C as class isn't taken...

Quick question regarding Conditional Compilation (ifndef)

Hello, This is quite probably a very silly question but I need to be sure. I've been given a class declaration in a header file eg. #ifndef file_H #define file_H class ex{ private: public: }; #endif and I've been required to write the method definitions in the same file, which I have done, my question is does the "#endif" stay wher...

How do C++ header files work?

Hi all. When I include some function from a header file in a C++ program, does the entire header file code get copied to the final executable or only the machine code for the specific function is generated. For example, if I call std::sort from the <algorithm> header in C++, is the machine code generated only for the sort() function or ...

Template Class Link-Time Error

Possible Duplicate: Why can templates only be implemented in the header file?? Hi, I have a c++ project which consists of several header and source files. In order to modify the class with a template, I found that all the method definitions must be included in the header file itself, else resulting in a link-time error. What ...

undefined reference errors in C++

I have files Record.h and Record.cpp. When I just include the Record.h file, I get several undefined reference errors to functions defined in those files. When I also include Record.cpp then the errors go away. Why is that? Record.h has the forward declarations for the functions it says are an undefined reference. Record.h #ifndef RECO...

Is it a good idea to work on header files only, just at the start of the project?

To explain my point further, I'm a beginner in programming, and I'm working on a small project. Instead of separating the .cpp file from the header file, I'm implementing the code in the header files, and making one .cpp file for testing. I do this to have less files, hence easier navigation. Then later I'll separate the code as it shou...

Cpp some basic problems

Hello. My task was as follows : Create class Person with char*name and int age. Implement contructor using dynamic allocation of memory for variables, destructor, function init and friend function show. Then transform this class to header and cpp file and implement in other program. Ok so here's my Person class : #include <iostream> usi...

Extract a C/C++ header file from a C# class exposed to COM

I'm not sure I've setup everything I've needed to in my C# class to properly, but it does work in COM. I've been looking for an example of a C# class that was successfully used in a C/C++ project, but haven't come across anything. I've tried using the OLE/COM Object View app to open the .tlb file and save as .h, but it gives some errors...