What is __declspec and when do I need to use it?
This is a Microsoft specific extension to the C++ language which allows you to attribute a type or function with storage class information.
Documentation
__declspec (C++)
The canonical examples are __declspec(dllimport)
and __declspec(dllexport)
, which instruct the linker to import and export (respectively) a symbol from or to a DLL.
// header
__declspec(dllimport) void foo();
// code - this calls foo() somewhere in a DLL
foo();
(__declspec(..)
just wraps up Microsoft's specific stuff - to achieve compatibility, one would usually wrap it away with macros)