auto readonly(T)(const(T)[] x) { return x; }

​

void main()

{

    auto             arr1 = [1, 2, 3];

    auto             arr2 = [1, 2, 3].readonly;

    const            arr3 = [1, 2, 3];

    enum             arr4 = [1, 2, 3];

    static immutable arr5 = [1, 2, 3];

    scope            arr6 = [1, 2, 3];

    pragma (msg, typeof(arr1)); // int[]

    pragma (msg, typeof(arr2)); // const(int)[]

    pragma (msg, typeof(arr3)); // const(int[])

    pragma (msg, typeof(arr4)); // int[]

    pragma (msg, typeof(arr5)); // int[]

    pragma (msg, typeof(arr6)); // int[]

    pragma (msg, "-----");

​

                     int[3]  arr7 = [1, 2, 3];

              const(int)[3]  arr8 = [1, 2, 3].readonly;

               const int[3]  arr9 = [1, 2, 3];

                enum int[3] arr10 = [1, 2, 3];

    static immutable int[3] arr11 = [1, 2, 3];

               scope int[3] arr12 = [1, 2, 3];

    pragma (msg, typeof(arr7));  // int[3]

    pragma (msg, typeof(arr8));  // const(int[3])

    pragma (msg, typeof(arr9));  // const(int[3])

    pragma (msg, typeof(arr10)); // int[3]

    pragma (msg, typeof(arr11)); // immutable(int[3])

    pragma (msg, typeof(arr12)); // int[3]

    static assert(is(const(int)[3] == const(int[3])));

    arr7 = arr1;

    //  arr8 = arr1; // Error: slice arr8[] is not mutable

    //  arr9 = arr1; // Error: slice arr9[] is not mutable

    // arr10 = arr1; // Error: arr10 is not an lvalue and cannot be modified

    // arr11 = arr1; // Error: slice arr11[] is not mutable

    arr12 = arr1;

    arr1 ~= 4;

    //  arr7 = arr1; // Array lengths don't match for copy: 4 != 3

    //  arr8 = arr1; // Error: slice arr8[] is not mutable

    //  arr9 = arr1; // Error: slice arr9[] is not mutable

    // arr10 = arr1; // Error: arr10 is not an lvalue and cannot be modified

    // arr11 = arr1; // Error: slice arr11[] is not mutable

    // arr12 = arr1; // Array lengths don't match for copy: 4 != 3

}