in K&R C or C89, inline was not part of the language. Many compilers implemented it as an extension, but there were no defined semantics regarding how it worked. GCC was among the first to implement inlining, and introduced the inline, static inline, and extern inline constructs; most pre-C99 compiler generally follow its lead. GNU89: … Read more
You should only use extern template to force the compiler to not instantiate a template when you know that it will be instantiated somewhere else. It is used to reduce compile time and object file size. For example: // header.h template<typename T> void ReallyBigFunction() { // Body } // source1.cpp #include “header.h” void something1() { … Read more
Using extern is only of relevance when the program you’re building consists of multiple source files linked together, where some of the variables defined, for example, in source file file1.c need to be referenced in other source files, such as file2.c. It is important to understand the difference between defining a variable and declaring a … Read more