我可以统一初始化模板类的静态const成员吗？

Question

I have a template class that looks something like this:

template <typename T>
class foo
{
    static const T arr[16];
};

The contents of foo<T>::arr are numerically identical for all types T that I plan to use. For example, I would initialize it for T = float and T = double by placing lines in a source file as follows:

float foo<float>::arr[16] = {1, 2, 3, 4, ...};
double foo<double>::arr[16] = {1, 2, 3, 4, ...};

Is there a way that I can initialize this in one place without having to repeat myself and enumerate all of the types that T can take on? Note that since the type of each array element is T , I can't use the trick of deriving foo<T> from a non-template base class that holds the static array.

Answer 1

What have you tried? This works for me:

#include <iostream>
using namespace std;

template<typename T>
struct Foo {
    static T const arr[16];
};

template<typename T>
T const Foo<T>::arr[16] = {1,2,3,4};

int main() {
    for ( float const *f = Foo<float>::arr; f != Foo<float>::arr+16; ++f ) {
        cout << *f << " ";
    }
    cout << endl;
    for ( double const *d = Foo<double>::arr; d != Foo<double>::arr+16; ++d ) {
        cout << *d << " ";
    }
    cout << endl;
}