Consider reading section 10.6.7 of the C# specification, which answers many of your questions. I reproduce part of it here for your convenience: When a method declaration includes an extern modifier, that method is said to be an external method. External methods are implemented externally, typically using a language other than C#. Because an external … Read more
Templates aren’t actual code, they’re just guidelines to the compiler for how to generate the code once the template parameters are known. As such they don’t actually exist until you try to use them. You can’t provide linkage to something that doesn’t exist.
If you do not specify a storage class (that is, the extern or static keywords), then by default global variables have external linkage. From the C99 standard: ยง6.2.2 Linkages of identifiers 3) If the declaration of a file scope identifier for an object or a function contains the storage-class specifier static, the identifier has internal … Read more
There’s surprisingly little in the standard about this. About all we hear about redeclaration is: [C++11: 3.1/1]: A declaration (Clause 7) may introduce one or more names into a translation unit or redeclare names introduced by previous declarations. [..] and the only relevant part of auto‘s semantics: [C++11: 7.1.6.4/3]: Otherwise, the type of the variable … Read more
no you can’t do it, here’s what the standard says (section 7.1.5): 1 The constexpr specifier shall be applied only to the definition of a variable or variable template, the declaration of a function or function template, or the declaration of a static data member of a literal type (3.9). If any declaration of a … Read more
A function definition with static inline defines an inline function with internal linkage. Such function works “as expected” from the “usual” properties of these qualifiers: static gives it internal linkage and inline makes it inline. So, this function is “local” to a translation unit and inline in it. A function definition with just inline defines … Read more
Global variables are not extern nor static by default on C and C++. When you declare a variable as static, you are restricting it to the current source file. If you declare it as extern, you are saying that the variable exists, but are defined somewhere else, and if you don’t have it defined elsewhere … Read more
It’s because const implies internal linkage by default, so your “definition” isn’t visible outside of the translation unit where it appears. In this case, by far the best solution is to put the declaration (extern int const n;) in a header file, and include that in both a.cpp and b.cpp. The linkage is determined by … Read more
The question is for VStudio 2010, but applies to any version. In C or C++, considering that a module may consist of multiple objects, every object should be clearly delimited. Also, every object (.c or .cpp file) should have its own header file. So, you should have one header file and one .c(xx) file for … Read more
You can use Web Workers ; MessageChannel , see How to clear the contents of an iFrame from another iFrame ; or window.postMessage() to communicate or pass variables between browsing contexts. An approach utilizing SharedWorker fileA.html <!DOCTYPE html> <html> <head> <script src=”https://stackoverflow.com/questions/36146595/scriptA.js”></script> </head> <body> <a href=”fileB.html” target=”_blank”>fileB</a> </body> </html> scriptA.js var x = 50, p; … Read more