How to define a const double inside a class's header file?

Question

Inside the header file of my class, I am trying the following and getting compiler complaints:

private:
    static const double some_double= 1.0;
         


        

Answer 1

Declare it in the header, and initialize it in one compilation unit (the .cpp for the class is sensible).

//my_class.hpp
private:
static const double some_double;

//my_class.cpp
const double my_class::some_double = 1.0;