ES6 will almost certainly not cover syntax for defining class variables. Only methods and getters/setters can be defined using the class syntax. This means you’ll still have to go the MyClass.classVariable = 42; route for class variables. If you just want to initialize a class with some defaults, there is a rich new syntax set … Read more
The rules have always been as follows: A const static data member (SDM) of integral or enumeration type can be initialised in class with a constant expression. A constexpr SDM must be initialised in class with a constant expression. C++17 no longer requires an initializer when the default constructor initialises every member. Also, constexpr SDMs … Read more
It is unspecified. Both compilers are right. Here are the relevant pieces from cppreference “initialization”. Static initialization For all other non-local static and thread-local variables, Zero initialization takes place So for all these variables, they are zero when the program loads. Then: Dynamic initialization After all static initialization is completed, dynamic initialization of non-local variables … Read more
You cannot override static methods or fields of any type in Java. public class User extends BaseModel { static String table = “user”; //snip } This creates a new field User#table that just happens to have the same name as BaseModel#table. Most IDEs will warn you about that. If you change the value of the … Read more
From the standard section 9.4.2: If a static data member is of const integral or const enumeration type, its declaration in the class definition can specify a constant-initializer which shall be an integral constant expression. In that case, the member can appear in integral constant expressions within its scope. The member shall still be defined … Read more
Definition needed The code you have provided is non-standard. While you can provide initializers for const static int members directly in the class, you still need to provide separate definitions. It is weird, a kind of unexpected, but you are expected to write it like this: #include <algorithm> struct Foo { static const int A … Read more
No, using static variables for this is not the way to go: If your AppDomain is recycled, all your static variables will be “reset” Static variables don’t scale horizontally – if you load-balance your application, a user who hits one server then a different one won’t see the data store in the static variables in … Read more
Yes. The static member is declared or defined inside the template< … > class { … } block. If it is declared but not defined, then there must be another declaration which provides the definition of the member. template< typename T > class has_static { // inline method definition: provides the body of the function. … Read more
If the function is only used in one source file, it makes perfect sense to define it there. If nobody else is using it, it doesn’t belong in the header. As you say, it reduces dependencies and can potentially save some recompiles.
Usually you should prefer std::string over plain char pointers. Here, however, the char pointer initialized with the string literal has a significant benefit. There are two initializations for static data. The one is called static initialization, and the other is called dynamic initialization. For those objects that are initialized with constant expressions and that are … Read more