constant variables not working in header

Question

if I define my constant varibles in my header like this...

extern const double PI = 3.1415926535;
extern const double PI_under_180 = 180.0f / PI;
extern cons         


        

Answer 1

A lot of incorrect responses below. The ones that are correct are the ones telling you to remove the extern as sellibitze has also said in his comment are correct.

Because these are declared const, there is no problem having the definition in the header. C++ will inline a const for a built in type unless you attempt to take its address (a pointer to a const) in which case it will instantiate it with static linkage, you may then also get multiple instantiations in separate modules, but unless you expect all pointers to the same const to have the same address, this is not a problem.