You have to ask yourself: “Am I targeting the problem with the adequated approach?” self:: and static:: do two different things. For instance self:: or __CLASS__ are references to the current class, so defined in certain scope it will NOT suffice the need of static calling on forward. What will happen on inheritance? class A … Read more
I had a similar problem and solved it by setting the lib project as a dependency of the main app project and then setting ‘Link Library Dependencies’ and ‘Use Library Dependency Inputs’ to Yes for the main project. Update: Recently I discovered that Visual Studio 2015 now supports a /WHOLEARCHIVE linker flag. I can’t find … Read more
You can’t define a static member variable more than once. If you put variable definitions into a header, it is going to be defined in each translation unit where the header is included. Since the include guards are only affecting the compilation of one translation unit, they won’t help, either. However, you can define static … Read more
Does it mean that a static constexpr variable is not odr-used (and therefore can be in-class initialized) if it is returned from a function? Yes. Essentially, as long as you treat it as a value, rather than an object, then it is not odr-used. Consider that if you pasted in the value, the code would … Read more
The One Definition rule tells us that we can not have more than one definition of an odr-used variable in a program. So if a variable is odr-used then you need to define it but you can not define it the header file since it may be included more than once with the whole program. … Read more
The declaration in an implementation file outside of the header is required because otherwise every translation unit that includes this header would define its own object (that is, its own storage for the variable). This would violate the One Definition Rule. A consequence would be e.g. that if the variable was changed in one translation … Read more
Because static class members are not stored in the class instance, that’s why a static would work. Storing an object inside another object of the same type would break the runtime – infinite size, right? What would sizeof return? The size of the object needs to be known by the compiler, but since it contains … Read more
It defines a pointer-to-function type. The functions return void, and the argument list is unspecified because the question is (currently, but possibly erroneously) tagged C; if it were tagged C++, then the function would take no arguments at all. To make it a function that takes no arguments (in C), you’d use: typedef void (*MCB)(void); … Read more
In the context of a class, static variables are on the class scope (not the object) scope, but unlike a const, their values can be changed. class ClassName { static $my_var = 10; /* defaults to public unless otherwise specified */ const MY_CONST = 5; } echo ClassName::$my_var; // returns 10 echo ClassName::MY_CONST; // returns … Read more
They will persist for the duration of AppDomain. Changes done to static variable are visible across methods. MSDN: If a local variable is declared with the Static keyword, its lifetime is longer than the execution time of the procedure in which it is declared. If the procedure is inside a module, the static variable survives … Read more