DEV Community: sydney

updating g++ compiler

sydney — Mon, 31 Jul 2023 17:04:35 +0000

I updated my MinGW compiler to the latest version and now when I look at g++ --version I get 201703 which I believe is version C++17! Unfortunately I'm looking at a tutorial that requires C++20! So does anyone know where to go to download version 20? I thought that the MinGW website had the latest and greatest version, but it seems that I am wrong in this assumption. Not the end of the world, but I would like to explore threads, so I need to update to version 20. Advice welcome on this one.
sydney / wt1v

updating compile for DevC++

sydney — Mon, 03 Jul 2023 02:10:21 +0000

I need to update the compiler in the DevC++ IDE. Maybe the tools/compiler options or the package manager is what I am looking for to do this task? I did look at the compilers for this IDE and they do seem to be a little bit on the older side, so it will not work with some of the newer features like supporting the string_view library! The documentation on how to update the compiler is non-existent as far as I can see!
syd/wt1v

string_view library

sydney — Sat, 01 Jul 2023 17:40:51 +0000

I have this project that includes . When I go to compile the project I get "[Error] string_view: No such file or directory" from the compiler. Sounds like a compiler issue but I have no idea what to do to fix it! Anyone know how to fix this problem?
syd / wt1v

cplusplus code example won't compile

sydney — Wed, 28 Jun 2023 17:01:11 +0000

#include <iostream> class base_class { public: virtual void vf1() = 0; //pure virtual virtual void vf2(); virtual void vf3(); }; class derived_class : public base_class { public: void vf1(); // OK if it is virtual also // virtual void vf1(); // virtual void vf2(int); virtual void vf3(); }; int main(int argc, char** argv) { //1 derived_class d; //2 base_class *bp = &d; //3 bp->vf1(); //4 bp->vf2(); //5 d.vf2(); } ERROR MSG: undefined reference tovtable for derived_class'

This code example, from cplusplus.com, does not compile when any of lines 1-5 are put in! It does when they are commented out, so the classes are OK. The error, line 1 in, points to the makefile line where the .exe file is created from the .o file! The .o file is in the project directory so that is not the problem. Creating the .exe file is. The above error msg is what I get when I compile with line 1 installed! Help!
syd / wt1v
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attaching to a post

sydney — Wed, 28 Jun 2023 16:22:00 +0000

I was going to make a post about problems with virtual functions and needed to attach some code snippets so anyone can see what I am talking about. It would be useless to talk about code without making an attached file of the code. I've done this same thing on several other forums, but I have yet to figure out how to do so with this forum. If I can't make a post with an attached file then this forum is useless! Please tell me I am missing something here!
syd / wt1v

adding a new file to a DevC++ project

sydney — Wed, 21 Jun 2023 14:21:44 +0000

When I create a new project, sooner or later I will want to add in some .h and .cpp files to the project. Selecting new file adds a file into the project and it's name is untitled1! Looking around at the properties menu and everything else that I could find, I still could not find any way of renaming the useless default name of the new file that I added to the project. One work around that I found is to create a new .txt file and rename it, and then add the empty renamed file into the project. I could also remove the untitled file from the project, then rename it to what I need, and then add this one into the project. There should be a simple way to rename the untitled file so I won't have to go through this fiasco!
syd / wt1v

vector code not compiling

sydney — Mon, 19 Jun 2023 15:49:32 +0000

I have this vector project that I made from some sites that contain example code using vectors. None of these
examples compile. Then, out of the blue, I got a header file that opened up with one line of code high lighted!
I have no idea how the DevC++ IDE opened this header file for the vector include library. One line was highlighted! It mentioned that I had to use a compiler parameter: "-std=C++1". So I went into compiler options and put this line in the C++ compiler parameters. Voila, now everything is compiling and the code example works as expected!!! So why didn't the original compiler work with vectors? I have no idea why that header file showed up? If I hadn't gotten lucky with that vector header file showing up, how would I have even solved the problem?
syd / wt1v

design pattern won't work

sydney — Sat, 10 Jun 2023 23:19:04 +0000

I was going to post an article about some C++ code that compiles but doesn't do anything upon opening the command window when run. There is no COUT presented in the window. All I get is a message
"process exited after 9.75 secs with return value 255"!!!
I tried running it in the debugger with a break point right after the main() so could enter into the code to see what is screwed up but all I get is the same error message and the break point seems to be ignored! The code compiles with no errors and warnings. I was going to attach the code to this post, but I don't see any way of making an attachment. Strange, attaching to a post works in all the other forums that I have joined! Whats going on here?
syd/wt1v

multiple DevC++ projects

sydney — Sat, 03 Jun 2023 19:50:33 +0000

I have several projects that I want to make from existing source code files from a C++ book in one folder. If I make a project and then install source files I will have a makefile for this project. Since I have several source files in the same folder I don't think making more than one project in the same folder will work out well because of multiple makefiles in the same folder. Any ideas on this predicament?
syd/wt1v

how do I attach images/files

sydney — Fri, 02 Jun 2023 18:21:14 +0000

I was going to make a post and I wanted to attach 3 small image files that cover what I'm talking about. But, in this forum I've yet to figure out how to attach files to the posted message on this forum. Is it possible to attach files to a newly created post? If so, how?
syd/wt1v

project won't compile

sydney — Tue, 23 May 2023 14:32:26 +0000

I am currently working with an older c algorithms book. I installed all the related .c and .h files into the project, but the compiler complains about "netinet/in.h " not being found even though it is included in the book code. The include line is #include and because of the <> brackets I was led to believe that this file is part of the installed library. I'm developing in a windows environment so I am a little bit confused about where this library file, if it even exist for windows, exists at all. If there is an alternative header file for windows where would I even go to download it?
sydney

DevC++ project problem

sydney — Thu, 18 May 2023 15:35:54 +0000

I have a DevC++ project that has a file that #includes netinet/in.h in it, but the compiler can't find this in.h library! The <> brackets that surround the .h include are <> and will not allow the #include to show up in this post. The <> indicate that this library should be in the compilers library of system files. This project was from an old c code book on algorithms, so maybe the code in not compatible with the newer compiler? How do I solve this library problem?
syd