_ What is the role of declspec (selectany )?

In the MFC, ATL Source code_ Declspec (selectany)
. Selectany allows us to initialize a global variable in the. h file instead of placing it in. cpp. For example, if there is a class with a static variable, we can
In the format of "_ declspec (selectany) type class: Variable = value;
" CodeTo initialize the global variable. This. H is included multiple times, and the linker also removes multiple definition Errors for us. What are the advantages of this?
Teamplate programming has a lot of convenience.