What is the <=> ("spaceship", three-way comparison) operator in …
Nov 24, 2017 · This is called the three-way comparison operator. According to the P0515 paper proposal: There’s a new three-way comparison operator, <=>. The expression a <=> b returns …
How to use the PI constant in C++ - Stack Overflow
Nov 13, 2009 · I want to use the PI constant and trigonometric functions in some C++ program. I get the trigonometric functions with include <math.h>. However, there doesn't seem to be …
What is the purpose of using #ifdef and #if in C++?
The meaning of #ifdef is that the code inside the block will be included in the compilation only if the mentioned preprocessor macro is defined. Similarly, #if means that the block will be …
Why can templates only be implemented in the header file?
Jan 30, 2009 · Have to recompile foo.cpp every time we change any other file in the program, in case it added a new novel instantiation of MyClass<T> Require that baz.cpp contains …
c++ - How can I convert a std::string to int? - Stack Overflow
Nov 20, 2014 · I want to convert a string to an int and I don't mean ASCII codes. For a quick run-down, we are passed in an equation as a string. We are to break it down, format it correctly …
How to call a parent class function from derived class function?
How do I call the parent function from a derived class using C++? For example, I have a class called parent, and a class called child which is derived from parent. Within each class there is …
When to use extern in C++ - Stack Overflow
I'm reading "Think in C++" and it just introduced the extern declaration. For example: extern int x; extern float y; I think I understand the meaning (declaration without definition), but I wonde...
Regular cast vs. static_cast vs. dynamic_cast - Stack Overflow
Aug 26, 2008 · I've been writing C and C++ code for almost twenty years, but there's one aspect of these languages that I've never really understood. I've obviously used regular casts i.e. …
How to throw a C++ exception - Stack Overflow
Feb 2, 2017 · I have a very poor understanding of exception handling(i.e., how to customize throw, try, catch statements for my own purposes). For example, I have defined a function as …
c++ - What is the difference between public, private, and …
Mar 19, 2015 · Only members/friends of a class can see private inheritance, and only members/friends and derived classes can see protected inheritance. public inheritance IS-A …