static

• Non-const global variables have external linkage by default
• Const global variables have internal linkage by default
• Functions have external linkage by default
• What’s the “static initialization order ‘fiasco’ (problem)”?
• C++ scoped static initialization is not thread-safe, on purpose! (pre-C++11)
• constinit
• static vs std::call_once vs double checked locking

• DCLP

  • Double-Checked Locking Pattern

• const and static variables don’t have external linkage.

Variables with static storage duration are zero initialised. Note that x has static storage duration even though the static keyword is not used. According to the standard: “All objects which do not have dynamic storage duration, do not have thread storage duration, and are not local have static storage duration”.

Only static_cast (or C-style casts) can be used to cast an int to an enum. Only reinterpret_cast (or C-style casts) can be used to cast an int to a pointer or a pointer to an int.