c++-faq Archives - Page 5 of 8

What are the main purposes of using std::forward and which problems it solves?

In perfect forwarding, std::forward is used to convert the named rvalue references t1 and t2 to unnamed rvalue references. What is the purpose ...

May 2, 2022
0 Comments

Iterator invalidation rules for C++ containers

This question’s answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. ...

April 30, 2022
0 Comments

Why is enum class preferred over plain enum?

I heard a few people recommending to use enum classes in C++ because of their type safety. But what does that really mean? ...

April 30, 2022
0 Comments

“std::endl” vs “\n”

Many C++ books contain example code like this… std::cout << "Test line" << std::endl; …so I’ve always done that too. But I’ve seen ...

April 29, 2022
0 Comments

Why is iostream::eof inside a loop condition (i.e. `while (!stream.eof())`) considered wrong?

I just found a comment in this answer saying that using iostream::eof in a loop condition is “almost certainly wrong”. I generally use ...

April 29, 2022
0 Comments

When can I use a forward declaration?

I am looking for the definition of when I am allowed to do forward declaration of a class in another class’s header file: ...

April 28, 2022
0 Comments

What does the C++ standard state the size of int, long type to be?

I’m looking for detailed information regarding the size of basic C++ types. I know that it depends on the architecture (16 bits, 32 ...

April 25, 2022
0 Comments

Why isn’t sizeof for a struct equal to the sum of sizeof of each member?

Why does the sizeof operator return a size larger for a structure than the total sizes of the structure’s members? 12 s 12 ...

April 21, 2022
0 Comments

What is object slicing?

In c++ what is object slicing and when does it occur? 18 s 18 Most answers here fail to explain what the actual ...

April 20, 2022
0 Comments

std::wstring VS std::string

I am not able to understand the differences between std::string and std::wstring. I know wstring supports wide characters such as Unicode characters. I ...

April 19, 2022
0 Comments