Where should a static const data member be defined?
c++, constants, initialization, static, static-members
Solution
Anywhere in one compilation unit (usually a .cpp file) would do:
foo.h
class foo {
static const string s; // Can never be initialized here.
static const char* cs; // Same with C strings.
static const int i = 3; // Integral types can be initialized here (*)...
static const int j; // ... OR in cpp.
};
foo.cpp
#include "foo.h"
const string foo::s = "foo string";
const char* foo::cs = "foo C string";
// No definition for i. (*)
const int foo::j = 4;
(*) According to the standards you must define `i` outside of the class definition (like `j` is) if it is used in code other than just integral constant expressions. See David's comment below for details.
Problem
I have a class ``` class foo { public: foo(); foo( int ); private: static const string s; }; ``` Where is the best place to initialize the string `s` in the source file?