I have simple project where I use tiny ttmath library for C++ (big nums).
This library consists of 13 *.h files.
I have included all these files in a stupid way:
#include "ttmath\ttmath.h"
#include "ttmath\ttmathbig.h"
#include "ttmath\ttmathdec.h"
#include "ttmath\ttmathint.h"
#include "ttmath\ttmathmisc.h"
#include "ttmath\ttmathobjects.h"
#include "ttmath\ttmathparser.h"
#include "ttmath\ttmaththreads.h"
#include "ttmath\ttmathtypes.h"
#include "ttmath\ttmathuint.h"
#include "ttmath\ttmathuint_noasm.h"
#include "ttmath\ttmathuint_x86.h"
#include "ttmath\ttmathuint_x86_64.h"
What is the right way? I expect smth like this:
#include "ttmath\*.h"
but can not find...
What is the right way? I expect smth like this:
#include "ttmath\*.h"
but can not find...
That won't work because the preprocessor is not going to expand characters to match things in the way you expect wildcards to work.
My recommendation would be to create a single custom header file of your own, and place all the #include entries in there. For example, in your .c file, you can add your own header:
#include "my_header.h"
And the contents of my_header.h would be:
#include "ttmath\ttmath.h"
#include "ttmath\ttmathbig.h"
#include "ttmath\ttmathdec.h"
#include "ttmath\ttmathint.h"
#include "ttmath\ttmathmisc.h"
#include "ttmath\ttmathobjects.h"
#include "ttmath\ttmathparser.h"
#include "ttmath\ttmaththreads.h"
#include "ttmath\ttmathtypes.h"
#include "ttmath\ttmathuint.h"
#include "ttmath\ttmathuint_noasm.h"
#include "ttmath\ttmathuint_x86.h"
#include "ttmath\ttmathuint_x86_64.h"
Basically, you put everything in a single header, and include that one instead.
The preprocessor doesn't have an "include all" built into it. Neither does it accept wildcards in filenames. You'll have to manually include all of them.
A common solution is to place all the includes in a new .h file and include that one every time you need all of them.
Related
Visual Studio 2022:
I want to Include Precompiled headers in my .cpp file but I don't know if it's worth it since I'll also need to include a non-precompiled header with almost the same headers that are in the precompiled header.
Will the non-precompiled header use the precompiled headers or will it generate the code again on each compilation?
CPP:
#pragma once
#include "Precompiled.h"
#include "No-Precompiled.h" // Basic Headers: Windows.h, Psapi.h
int main()
{
// Functions that I need from "No-Precompiled.h" but I can't Precompile it since changes in it are made on regular basis
}
No-Precompiled.h:
#pragma once
#include <windows.h>
#include <Psapi.h>
#include <d3d11.h>
class Template
{
public:
//Functions that need many same Headers.
}
Precompiled.h:
#pragma once
#include <windows.h>
#include <Psapi.h>
#include <d3d11.h>
#include <limits>
#include <complex>
#include <filesystem>
#include <iostream>
#include <string>
#include <chrono>
#include <thread>
#include <tchar.h>
#include <wincred.h>
#include <complex>
#include <math.h>
Should I just Precompile the headers that the .cpp file uses (which is not much) or is there a way to allow No-Precompiled headers to use the Precompiled headers?
Using pre-compiled headers doesn't change that much. In particular, header guards continue to work. The header guard for <windows.h> is also included in the pre-compiled state. Hence, when the compiler sees <windows.h> for the second time, it's immediately skipped.
In your case, the No-Precompiled.h header turns out to be pretty trivial, as all its headers have already been included. You're just compiling the Template.
I'd wonder a bit about the particular set of precompiled headers, though. PSapi and DirectX and IOstream? I can't really imagine a big program where you have many files using all of them. Note that <iostream> is really about std::cout, which doesn't make a lot of sense for DirectX programs.
I've seen several questions discussing this topic but none of their solutions seems to apply here. I have several libraries that I don't wont to be compiled every time I build the project so I've created "b5pch.h" and b5pch.cpp" files.
//b5pch.h
#pragma once
#include <iostream>
#include <memory>
#include <utility>
#include <algorithm>
#include <functional>
#include <sstream>
#include <string>
#include <vector>
#ifdef B5_PLATFORM_WINDOWS
#include <Windows.h>
#endif
//b5pch.cpp
#include "b5pch.h"
In properties I've set precompiled header for every cpp file to be Use(/Yu) like so:
And for b5pch.cpp it's set to Create(/Yc)
after that I've added #include "b5pch.h at the start of each cpp file(I only have two not including b5pch.cpp) but when I try to build the project I get two errors saying exactly the same thing
Error C1010 unexpected end of file while looking for precompiled header. Did you forget to add '#include "b5pch.h"' to your source?
Okay I've fixed the problem. when I was including b5pch.h in my cpp files I was doing it like this:
#include ../b5pch.h since they were in different directories.
When I moved pch files in same directory and I just wrote #include b5pch.h there were no more errors. I didn't wanted them to be in same folder so I've moved them back out but in Project Properties->Additional Include Directories I've added "src" so I could just use #include b5pch.h in my cpp files even tho they were not in the same folder.
I get the error:
no operators ">>" match these operands.
and
string is not a member of std.
#include "iostream"
#include "string.h"
#include "stdafx.h"
int main()
{
std::string forName;
std::cout << "Write your name below please:/n";
std::cin >> forName;
std::cout << forName;
}
Unless you're trying to include your own header files, include statements in C++ should use angular brackets:
#include <iostream>
#include <string.h>
#include <stdafx.h>
Also, if you're writing C++: I suggest that you use <string> instead of <string.h>, because the latter is a C header (not C++) and is deprecated in C++. If not then ignore this bit :)
Everything included above #include "stdafx.h" is ignored by Visual Studio. More information on why this is can be found here: What's the use for "stdafx.h" in Visual Studio?
So
#include "iostream"
#include "string.h"
#include "stdafx.h"
Must be
#include "stdafx.h"
#include "iostream"
#include "string.h"
After that you can optimize the searching for the include files by surrounding headers with the appropriate <> or "". Selecting which to use is covered here: What is the difference between #include <filename> and #include "filename"?
In addition, string.h is a C header for C string utilities. It does not include the class string. For that you need
#include <string>
If you do want the C string utilities, it is recommended you use the C++ version
#include <cstring>
You need to change the quotation marks to angle brackets.
#include <iostream>
#include <string>
#include <stdafx.h>
See this question for more information about the difference between the two: Difference between angle bracket < > and double quotes " " while including header files in C++?
If you have your own header file then include like this:
#include "yourheader.h"
But if you are using standard header file then you have to include like this:
#include <iostream>
You must replace #include "filename" with #include <filename>
For #include "filename" the preprocessor searches in the same directory as the file containing the directive. This method is normally used to include programmer-defined header files.
For #include <filename> the preprocessor searches in an implementation dependent manner, normally in search directories pre-designated by the compiler/IDE. This method is normally used to include standard library header files.
The string.h library is actually deprecated within C++. Try using string instead, or if you need functionality that is from string.h (strcpy, strlen), try using cstring.
so here the problem i have 13 include files in my program (and i am willing to include more!) but the problem is that the compiler is ignoring the last include and i can say so because i switched between two of them and the error will be always for the last lien the line number 13
here are the include files
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>
#include <vector> //for dynamic tables
#include <string>
#include <conio.h>//used for the function getch
#include "checkPassword.hpp"
#include "buffervoider.hpp"
#include "checktyping.hpp"
#include "extractline.hpp"
#include "getchoic.hpp"
#include "tableidentify.hpp"
the error here will be:
|error: 'tableidentify' was not declared in this scope|
but if i switch between #include "getchoic.hpp" and #include "tableidentify.hpp"
the error would be
|error: 'getchoic' was not declared in this scope|
also all my headers have include guards
so how to solve this problem ?
If those hpp files are yours, then remove the #include in one of them that includes the other so if tableidentify.hpp has #includes getchoic or vice versa, remove one of the includes to the other
You probably baby have circular includes: one file includes another, which includes the first.
I'm assuming that some of those headers are user defined (i.e. you made them). If so, try combining all of the user-defined header include statements in another header, then including that.
I am finding some issue in the order the include headers are defined in the c / c++ files when i execute pclint.
Say the include order is ,
#include <sys/timerfd.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
and when i execute the pclint it gives error in say , FILE is un declared etc.
Later i changed the order of include to
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <stdarg.h>
#include <string.h>
#include <sys/timerfd.h>
i could see that many errors were gone . I am not able to figure out why is this behavior. I am using PC-lint for C/C++ (NT) Vers. 8.00w.
i have marked the include path as say, +libdir(D:\timesys\nitrogen6x\toolchain\include)
Thank You
Brijesh
Supposedly, the inclusion of header files does slightly matter, although it's rare to find such an occasion. Some include files use types, enums or something else that is only defined in another include file.
On Linux, for example, some functions require the inclusion of multiple headers. Some of the programs using those, fail if you include those headers in the wrong order.
Kinda like the final linking stage. You have to set the libs in the correct order, otherwise you may get unresolved dependencies.
If I find an example, i will post it here.
EDIT:
Found an example. Qt. Qt has the most absurdly complicated set of headers. If you include, for example, opengl.h before QtOpenGL.h, it gives you a compilation error, because inside the Qt headers it checks for the inclusion of opengl. For some reason, QtOpenGL.h must come first.