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reflectiondcompile-time

How do you enumerate the names and types inside a struct or class at compile time in D?


How do you enumerate the names and types inside a struct or class at compile time?

i.e. to do the following:

struct Foo {
  int x;
  int y;
}

string serialise!(A)(A a) {
  ...magic...
}

auto f = Foo(1,2);
serialise(f); -> "x:1, y:2"

Thanks,

Chris.


Solution

  • Like this:

    foreach (index, field; myStruct.tupleof)
    {
        // field.stringof is "field", slice is to cut off "myStruct."
        pragma(msg, "Name: " ~ myStruct.tupleof[index].stringof[9..$]);
        pragma(msg, "Type: " ~ typeof(field).stringof);
    }
    

    Practical example: https://github.com/CyberShadow/ae/blob/master/utils/json.d#L107