Undefined reference to static constexpr char[]

Question

I want to have a static const char array in my class. GCC complained and told me I should use constexpr, although now it\'s telling me

Answer 1

Add to your cpp file:

constexpr char foo::baz[];

Reason: You have to provide the definition of the static member as well as the declaration. The declaration and the initializer go inside the class definition, but the member definition has to be separate.