Macro

[ankushnandan]

#ifdef  __cplusplus
extern "C" {
#endif 

What Does Above macro means

[hamsterman]

http://msdn.microsoft.com/en-us/library/0603949d(v=vs.80).aspx

In C++, when used with a string, extern specifies that the linkage conventions of another language are being used for the declarator(s)

#ifdef part is there because you don't need to specify C linkage if your writing code in C.