Beginners

by admin
Welcome -- read before posting!
 
Welcome to the beginner's forum in C++.com! In this forum, users can to talk about any topic relate...
[2 replies] Last: How To Answer Questions in a Helpful Way Be gentle. Problem-relat... (by admin)
Console Closing Down (1,2,3,4,5,6,7)
 
Hi, i am new to C++ and have just written my "Hello World" program. It worked all right but the cons...
[120 replies] Last: It displayed "Hello world" after you pressed Enter. int c is a ... (by Duthomhas)
by Atom1
DLL Calculation does not agree with Excel (1,2)
 
I'm trying to understand why the DLL built from the code below does not get the same result as Excel...
[20 replies] Last: Array Values Old Method DLL 848 5 4516.72552 0.9981800000 ............ (by lastchance)
by chipp
C++20 import issue
 
i tried to code in C++20 and tried to import header file but it doesn't worked anyone knows why? ...
[7 replies] Last: but there's no "Latest" option Look at the option below C++20, the o... (by George P)
make_pair with explicit types
 
Good day! I have problem understanding why my example is not compiling when I explicitly specify th...
[7 replies] Last: Thank you for answers! It became a lot more clear now! @Peter87, Abou... (by Satoshi Yoda)
by Ch1156
Best way to lock a thread mutex?
 
So if I wanted to lock a mutex, could use mut.lock() and mut.unlock(), but the more modern way to do...
[3 replies] Last: Awesome thank you both! (by Ch1156)
by Ch1156
Re-validating an iterator (1,2)
 
I wrote a simple program that removes all people from the vector based on age. Normally, when i writ...
[25 replies] Last: Thanks for all the info, ill set that up at some point here soon. For ... (by Ch1156)
by Atom1
DLL is not a valid win32 aplication
 
I recently migrated from VS 2019 to VS 2022. When I try to run debug on this code, I get a message b...
[8 replies] Last: Also just a small point. if you want to debug a dll then the dll needs... (by seeplus)
got undefined symbol: _ZTIN9... when run executive file
 
Hello everyone! This morning I have got unexpected error: "undefined symbol: _ZTIN9Fastcgipp3SQL12R...
[7 replies] Last: [quote=kigar64551]But keep in mind... Thank you. btw, I hope there w... (by spistol)
Output Iterators: What does it mean that "we may assign to a given value of an output iterator only once"?
 
From C++ Primer, Lippman, Section 10.5.1. "The Five Iterator Categories" Output Iterators can be t...
[1 reply] : > 1. What does it mean when the author says "we may assign to a given ... (by JLBorges)
C++ GUI QT (Trafic Light)
 
I have to write a GUI application for Traffic light - Green/Yellow/Red im allowed to specify the tim...
[10 replies] Last: Use a QVBoxLayout ? https://doc.qt.io/qt-6/qvboxlayout.html#details... (by kigar64551)
How to write a class that can be written out to ostream_iterator and read from istream_iterator?
 
I'm reading C++ Primer, Lippman, the chapter on stream iterators and in particular on istream and os...
[10 replies] Last: > Can I specify specific input stream types instead of istream& operat... (by JLBorges)
by Feit
Producing a specific pattern
 
I am trying to produce a specific pattern (shown below) using C programming. I wrote the following c...
[3 replies] Last: Many thanks. (by Feit)
How to use extern to refer to an external variable with the same name as variable declared statically?
 
In the function increment() below, how do I refer to sameName from file2.cpp? main.cpp #i...
[3 replies] Last: [quote=JLBorges]This violates ODR I see. I just wanted to understand... (by ElusiveTau)
Why CMake doesn't see -std=c++20?
 
Hi there! I'm trying to install an library. After the "make" command, there are a lot of errors reg...
[6 replies] Last: If cppreference is to be believed even GCC 13 is not 100% compliant wi... (by George P)
user adds vector
 
Anyone know a good method for letting a user add a new vector and access all vectors created...in a ...
[4 replies] Last: As a starter for 10, consider: #include <map> #include <vector> #in... (by seeplus)
Back Up Microsoft Visual Sudio Project? (1,2)
 
Hi, Sorry if this is the wrong forum... I am using Microsoft Visual Studio 2019 and would like...
[22 replies] Last: Another way to backup code: Use a NAS (Networked Attached Storage). I ... (by ElusiveTau)
by Ch1156
Does this code look fine
 
Ive been practicing with using iterators with vectors, vectors of pairs and maps, this happens to be...
[3 replies] Last: Compare offers a potential use-case for range projections. Could be... (by mbozzi)
3D C++ array
 
This feels like a pretty simple question, but I keep getting my indexing incorrect/confused here. Ba...
[3 replies] Last: Have you considered vector<vector<vector<double> > > ? The code will ... (by dhayden)
An array of vectors
 
Just wondering how to have an array of vectors. I tried reading this.... https://www.codespeedy.com...
[8 replies] Last: Got it working now... I changed using Image = std::vector<char>; ... (by Cyclone)
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