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How do I declare the type of a template constant?

If I do a typedef like

typedef int const cint;

cint

will refer to an int which cannot be modified. I can use cint

in any context that accepts a type (template parameter, function definition, etc.).

However, typedefs don't work with templates. I hope you can declare a template, for example Constant<SomeType>

, and refer to const SomeType

how I can do with the cint

above. Is it possible?

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2 answers


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;
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std::add_const_t<SomeType>

matches const SomeType

.



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