c++ - Does instantiating a template instantiate its static data members? -

c++ - Does instantiating a template instantiate its static data members? -

with regard explicit instantiation (iirc used when template declare in header , defined in cpp file because otherwise linker not able find when using somewhere else), if template has static fellow member variable, explicit instantiation instantiate , create static fellow member variable?

if explicitly instantiate class template, non-template members instantiated, including static info members long have definition. example:

template <typename t> struct foo { static int static_data; void non_template_member() {} template <typename s> void template_member(s) {} }; template <typename t> int foo<t>::static_data = 0; template struct foo<int>; template struct foo<double>;

the explicit instantiations @ bottom create definitions static_data , non_template_member() types int , double. there won't definition template_member(s) still open set.

if not provide [templated] definition static_data, won't instantiate corresponding definition.

the relevant section of standard 14.7.2 [temp.explicit] paragraph 8:

an explicit instantiation names class template specialization explicit instantiation of same kind (declaration or definition) of each of members (not including members inherited base of operations classes , members templates) has not been explicitly specialized in translation unit containing explicit instantiation, except described below.

without fellow member definition static fellow member declared , explicit instantiation simply see declaration beingness instantiated. definition explicit instantiation becomes definition.

c++ templates