How can I declare a template constant type?

Question

If I make a typedef such as

typedef int const cint;

cint will refer to an int that can't be modified. I can use cint in any context that takes a type (template parameter, function definition, etc).

However, typedefs don't work with templates. My hope is to be able to declare a template like Constant<SomeType> and have this refer to a const SomeType , the way I can do with cint above. Is it possible?

Answer 1

C++11:

template <typename T>
using Constant = const T;

Constant<int> i = 1;
//! i = 2; // error: assignment of read-only variable 'i'

C++03:

template <typename T>
struct Constant
{
    typedef const T type;
};

Constant<int>::type i = 1;

Answer 2

std::add_const_t<SomeType>与const SomeType相同。