C++ template specialization for pointer?

Question

I read book < C++ Templates - the Complete Guide > and learned template specialization for pointer. (maybe I misunderstand this part of the book)

(1) Here\'s my s

Answer 1

Two problems:

1. You are not allowed to partially specialise a function.

2. The behaviour of (void*)0x25 is undefined. With the exception of nullptr, you are not allowed to set a pointer to memory you don't own, with the exception of one past the final element of an array and one past the address of a scalar.

Answer 2

The error message told you what is wrong:

non-type partial specialization ‘Function<T*>’ is not allowed

You can only partially specialize types (classes). You've tried to partially specialize a function. Functions are not types; you can only fully specialize them.

Answer 3

as you've been already told, partial specialization of function templates are not allowed. You can use std::enable_if for this:

template <typename T, typename std::enable_if_t<!std::is_pointer<T>::value>* = 0>
void func(T val) { std::cout << val << std::endl; }

template <typename T, typename std::enable_if_t<std::is_pointer<T>::value>* = 0>
void func(T val) { func(*val); }

If you are looking for simpler syntax, wait for concepts