Частичная специализация шаблона класса для константных и неконстантных указателей ⇐ C++

[Anonymous]

I am trying to make a class template with non-type template parameter of pointer type, which has two specializations for const and not-const pointers.

This is my best attempt, accepted by Clang and GCC:

template struct A {}; template struct A; int v; A a; but A still uses the primary template with const pointer despite &v has type int*.

On the other hand, MSVC prints:

error C2753: 'A': partial specialization cannot match argument list for primary template Online demo: https://godbolt.org/z/EzoYoxEza

Is my partial specialization correct? And if yes, how can I use A?

Another attempt was to declare the primary template with auto non-type template parameter and specialize it twice:

template struct A; template struct A {}; template struct A; int v; A a; It works fine with GCC, but both Clang and MSVC complain:

Clang error: ambiguous partial specializations of 'A' MSVC error C2752: 'A': more than one partial specialization matches the template argument list Online demo: https://godbolt.org/z/43bj6EWq6

Considering that all compilers agreed in the previous example that template is more specialized than template , which one is correct here?


Источник: https://stackoverflow.com/questions/777 ... t-pointers