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 …
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 …
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 C++ function to raise a number to a power?
In C++ the "^" operator is a bitwise XOR. It does not work for raising to a power. The x << n is a left shift of the binary number which is the same as multiplying x by 2 n number of times and …
Why are #ifndef and #define used in C++ header files?
I have been seeing code like this usually in the start of header files: #ifndef HEADERFILE_H #define HEADERFILE_H And at the end of the file is #endif What is the purpose of this?
How to generate a random number in C++? - Stack Overflow
Nov 19, 2012 · I'm trying to make a game with dice, and I need to have random numbers in it (to simulate the sides of the die. I know how to make it between 1 and 6). Using #include …
Iterate through a C++ Vector using a 'for' loop - Stack Overflow
Oct 3, 2012 · I am new to the C++ language. I have been starting to use vectors, and have noticed that in all of the code I see to iterate though a vector via indices, the first parameter of …
c++ - How can I trim a std::string? - Stack Overflow
} // The remaining functions (trim() et al.) are identical to the new C++11 version std::ptr_fun is needed to disambiguate std::isspace because there is a second definition which supports …
What's the difference between constexpr and const?
What's the difference between constexpr and const? When can I use only one of them? When can I use both and how should I choose one?
Proper way to initialize C++ structs - Stack Overflow
Jan 21, 2017 · Our code involves a POD (Plain Old Datastructure) struct (it is a basic c++ struct that has other structs and POD variables in it that needs to get initialized in the beginning.) …