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 have got the following questions: When should I use std::wstring over std::string? Can std::string hold the entire ASCII character set, including the special characters? Is std::wstring supported by all popular C++ compilers? … Read more
How do I setup a class that represents an interface? Is this just an abstract base class? 17 s 17 To expand on the answer by bradtgmurray, you may want to make one exception to the pure virtual method list of your interface by adding a virtual destructor. This allows you to pass pointer ownership … Read more
In many C/C++ macros I’m seeing the code of the macro wrapped in what seems like a meaningless do while loop. Here are examples. #define FOO(X) do { f(X); g(X); } while (0) #define FOO(X) if (1) { f(X); g(X); } else I can’t see what the do while is doing. Why not just write … Read more
What is it? What does it do? When should it be used? Good links are appreciated. 8 s 8
I wrote these two solutions for Project Euler Q14, in assembly and in C++. They implement identical brute force approach for testing the Collatz conjecture. The assembly solution was assembled with: nasm -felf64 p14.asm && gcc p14.o -o p14 The C++ was compiled with: g++ p14.cpp -o p14 Assembly, p14.asm: section .data fmt db “%d”, … Read more
When asking about common undefined behavior in C, people sometimes refer to the strict aliasing rule. What are they talking about? 1Best Answer 11 A typical situation where you encounter strict aliasing problems is when overlaying a struct (like a device/network msg) onto a buffer of the word size of your system (like a pointer … Read more
I want to convert a std::string to lowercase. I am aware of the function tolower(). However, in the past I have had issues with this function and it is hardly ideal anyway as using it with a std::string would require iterating over each character. Is there an alternative which works 100% of the time? 27 … Read more
In C++, is there any difference between: struct Foo { … }; and: typedef struct { … } Foo; 8 s 8 In C++, there is only a subtle difference. It’s a holdover from C, in which it makes a difference. The C language standard (C89 §3.1.2.3, C99 §6.2.3, and C11 §6.2.3) mandates separate namespaces … Read more
I’m currently using the following code to right-trim all the std::strings in my programs: std::string s; s.erase(s.find_last_not_of(” \n\r\t”)+1); It works fine, but I wonder if there are some end-cases where it might fail? Of course, answers with elegant alternatives and also left-trim solution are welcome. 48 s 48
I stumbled upon Stack Overflow question Memory leak with std::string when using std::list<std::string>, and one of the comments says this: Stop using new so much. I can’t see any reason you used new anywhere you did. You can create objects by value in C++ and it’s one of the huge advantages to using the language. … Read more