Does D have a system expressive enough to make it work dynamically?

Question

Does D have a sufficiently expressive type system to make it dynamically executable (i.e., with multiple value classes) in a statically typed structure?

I ask by reading Dynamic languages ​​- these are static languages. The sample code, if any, is highly appreciated.

Answer 1

If you use std.variant.Variant , then D is essentially a dynamically typed language. Here is an example of its use from the library help page:

 Variant a; // Must assign before use, otherwise exception ensues // Initialize with an integer; make the type int Variant b = 42; assert(b.type == typeid(int)); // Peek at the value assert(b.peek!(int) !is null && *b.peek!(int) == 42); // Automatically convert per language rules auto x = b.get!(real); // Assign any other type, including other variants a = b; a = 3.14; assert(a.type == typeid(double)); // Implicit conversions work just as with built-in types assert(a > b); // Check for convertibility assert(!a.convertsTo!(int)); // double not convertible to int // Strings and all other arrays are supported a = "now I'm a string"; assert(a == "now I'm a string"); a = new int[42]; // can also assign arrays assert(a.length == 42); a[5] = 7; assert(a[5] == 7); // Can also assign class values class Foo {} auto foo = new Foo; a = foo; assert(*a.peek!(Foo) == foo); // and full type information is preserved