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arrayssyntaxdimmutabilityimmutablearray

Mutable array of immutable length in D

Is it possible in D to have a mutable array of which the length is not known at compile time to have a static length? 

void testf(size_t size) {
    int immutable([]) testv = new int[](a);
}
Solution

  • Nope, at least not unless you provide your own array wrapper. You could do something like:

    struct ImmutableLength {
     int[] array;
     alias array this; // allow implicit conversion to plain array
     this(int[] a) { array = a; } // initialization from plain array
     @property size_t length() { return array.length; }
     @disable @property void length(size_t) {}
     @disable void opOpAssign(string op: "~", T)(T t) {}
     @disable void opAssign(int[]) {}
 }

    Notice the disabled length setter and append operator which pretty much implements what you want.

                auto i = ImmutableLength([1,2,3]); // declare it like this