Template specialization static member initialization

Given that explicit instantiation happens in the header file. No it doesn't. At least, it doesn't have to, and putting it there would be a bad idea. Let me try and spell it out more precisely:. Unfortunately that makes it impossible for each specialization to provide it's own initial value for the static variable, which is the whole point of what I'm trying to do.

Put this into the same header file:. It's annoying that I have to put the initialization of the static in the header: in my actual application there are several static members, some of which are complex structures, and the initialization can get quite bulky. But still, I can live with that as long as it works.

Given that explicit instantiation happens in the header file I would have thought that each OBJ which included the header would end up with it's own copy of the statics. But even when crosslinking between DLLs everyone appears to be sharing the same instantiation. That all compiles without any errors. The wrappedFloat class is set up similarly and it too compiles cleanly. I put both classes into a DLL and then link it into a mainline which calls both class's func methods:.

I assume that this is because neither wrappedInt nor wrappedFloat are marked for export. I figured out what was happening there. Without the dllexports no export lib was being generated. New Post. Isn't this legal code to initialize a static member of a template class? First time posters: Do this! Follow Post Reply. Jacek Dziedzic. HTH, - J. Rob Williscroft. Alternative representations. Boolean - Integer - Floating-point. Implicit conversions - Explicit conversions.

Class declaration. Access specifiers. Virtual function. Default constructor. Copy constructor. Copy assignment. Class template. Function template. Template specialization. Parameters and arguments. Function templates. Class member templates.

Template argument deduction. Explicit full specialization. Partial specialization. Dependent names. Contents 1 Syntax 2 Explanation 3 Class template instantiation 3. In the case of the partial specialization in line 2, you can only choose the type. This means the 3-dimensional space is reduced to a line. The partial specialization of the primary template Matrix is, therefore, a subspace of the 3-dimensional space.

The full specialization line 3 stands for a point in the 3-dimensional space. The question is: What happens when you instantiate Matrix for various template arguments? Here are three instantiations, and you see what the compiler creates. To understand this process, you have to keep a few rules in mind.

Here are the rules that apply, in particular, to the partial specialization of class templates. Okay, there is one question left I have to answer.

What does it mean that a template A is a more specialized template than another template B. This is my informal definition. If you want to have it more formal, visit cppreference. For example, partial or full specialization behaves like a compile-time if and full specialization of class or function templates are quite similar to ordinary classes or functions. My special thanks to Embarcadero.

My special thanks to PVS-Studio. I'm happy to give online seminars or face-to-face seminars worldwide.