What is the lifetime of class static variables in C++?

Simply speaking:
A static member variable is constructed when the global variables are constructed. The construction order of global variables is not defined, but it happens before the main-function is entered.

Destruction happens when global variables are destroyed.

Global variables are destroyed in the reversed order they were constructed; after exiting the main-function.

Regards,
Ovanes

P.S.: I suggest to take a look at C++-Standard, which explains (defines) how and when global or static member variables are constructed or destructed.

P.P.S.: Your code only declares a static member variable, but does not initialize it. To initialize it you must write in one of the compilation units:

std::vector Test::staticVector;
or
std::vector Test::staticVector=std::vector(/* ctor params here */);

Some specific VC++ information in case that's what you're using:

1. Static class variables construction occurs at same time as other static/global variables.
2. In windows, the CRT startup function is responsible for this construction. This is the actual entry point of most programs you compile (it is the function which calls your Main/Winmain function). In addition, it is responsible for initializing the entire C runtime support (for example you need it to use malloc).
3. The order of construction is undefined, however when using the microsoft VC compiler the order of construction for basic types will be OK, for example it is legal and safe to write

statics.h: ... MyClass declaration ... static const int a; static int b; static int ar[]; } statics.cpp:

const int MyClass::a = 2;
int MyClass::b = a+3;
int MyClass::ar[a] = {1,2}