This code

import std.sumtype: SumType;

struct A
{
    SumType!int b;
}

static foreach(sym; __traits(allMembers, A))
    pragma(msg,sym);

prints

b
opAssign

How can I check that opAssign is generated by compiler and doesn't exist in the original code?

On Friday, 25 February 2022 at 05:25:14 UTC, Ali Çehreli wrote:

This take a struct as an argument, not a member, so I need to do if(sym == "opAssign"). I gave this another thought and checking the symbol against "opAssign" would be good enough for my use case.

Another interesting observation - is there any explanation why typeof returns different results for generated opAssign?

import std.sumtype: SumType;

struct A
{
    SumType!int b;
}

static foreach(sym; __traits(allMembers, A))
{
    // ref A(A p) return,opAssign
    pragma(msg,
              typeof(__traits(getMember, A, sym)).stringof,",",sym);

    // true,pure nothrow @nogc ref @safe A(A p) return,opAssign

    pragma(msg,
           is(typeof(__traits(getMember, A, sym)) == function),",",
              typeof(__traits(getMember, A, sym)).stringof,",",sym);

	// pure nothrow @nogc ref @safe A(A p) return,opAssign
    pragma(msg,
              typeof(__traits(getMember, A, sym)).stringof,",",sym);
}

If I move foreach loop into a function (e.g. main) then the first pragma prints the same as the others.

On Friday, 25 February 2022 at 14:25:22 UTC, Andrey Zherikov wrote:

It sounds like this is probably an inconsistency in .stringof, not typeof. I couldn't say what causes it, but it's not the first time I've seen .stringof give inconsistent results. (E.g., https://issues.dlang.org/show_bug.cgi?id=18269)

On Friday, 25 February 2022 at 16:24:46 UTC, Paul Backus wrote:

I see. Thanks