Category "c++"

Can I list-initialize a vector of move-only type?

If I pass the following code through my GCC 4.7 snapshot, it tries to copy the unique_ptrs into the vector. #include <vector> #include <memory> in

Can casts be completely avoided with a good design?

I'm wondering whether situation exists where casting is completely necessary. I'm talking here about casts between classes, not basic types. Is casting (be it

How to execute a piece of code only once?

I have an application which has several functions in it. Each function can be called many times based on user input. However I need to execute a small segment o

Correct way to find nth root using pow() in c++

I have to find nth root of numbers that can be as large as 10^18, with n as large as 10^4. I know using pow() we can find the nth roots using, x = (long int)(1

Video Poker in C++

I'm starting to write a video poker program and I'm running into some issues. I have a Hold function as you can see below: void Game::Hold( bool& choice

Linux script executing from C++ code with execv fails

I've a very basic Linux script (/home/scripts/script.sh): #!/bin/bash echo 'a' | /bin/netcat -vv 10.10.10.1 3333 echo "done" > /tmp/result When I try to r

Qt: How to change cursor by using style sheets?

I know I can change the cursor by "setCursor(const QCursor &)". Now I want to change it by using qss, but I don't know how to do it. QWidget has the cursor

How do I call ::std::make_shared on a class with only protected or private constructors?

I have this code that doesn't work, but I think the intent is clear: testmakeshared.cpp #include <memory> class A { public: static ::std::shared_pt

cppcheck How to suppress inline unmatched suppression?

I found that --suppress=unmatchedSuppression only suppresses unmatched suppression types in cppcheck options, but NOT unmatched inline suppressions. Is this t

worth the time investment to learn Qt (c++)? [closed]

i already know java, c++ (no one framework for GUI development) and little of c# (winforms for gui development) but i'm thinking to ivest my f

Why does QStringLiteral returns a garbled string

I'm programming a Chinese software, and embed some of the strings in the source file. To reduce runtime overhead (well, actually this is premature optimization,

C++ object hierarchy - how to manage circular dependencies?

I want to make two classes: an object and an object_manager, but I'm confused about how they should see/include each other. I've heard that it's forbidden for t

ROS2: how to create an Int8MultiArray

This is a ROS2 beginner question I've tried to use several ROS sources which suggested me to include "std_msgs/Int8MultiArray.h". However, if I do that I will g

Is there a functional difference between "2.00" and "2.00f"?

I ask because I am using the Box2D library, which calls for mostly float arguments. Although I see a lot of example code that uses the 0.00f format, I am not qu

What is a constant reference? (not a reference to a constant)

Why do constant references not behave the same way as constant pointers, so that I can actually change the object they are pointing to? They really seem like an

Restricting header inclusions in C++

What is the best way to restrict use of certain headers(features of the library itself) in certain Cpp files. And if it fails to follow the set rules, compilati

How is a Vector of Vector aligned in memory?

I understand as Set size of vector of vectors at run time describes, one can declare vector of vector as vector<vector<int> > ref; then resize t

isPalindrome homework exercise

Write a program that uses the function isPalindrome given in Example 6-6 (Palindrome). Test your program on the following strings: madam, abba, 22, 67876, 4

Should virtual dispatch happen when a virtual method is called within a virtual method using object?

struct B { virtual void bar () {} virtual void foo () { bar(); } }; struct D : B { virtual void bar () {} virtual void foo () {} }; Now we call foo()

C++ What is the difference between definition and instantiation?

What is the difference between definition and instantiation? Sub-question: Are "variable definition" and "variable instantiation" the same? int x; The above