Re: How do I check if this field is of this template struct?

[Jack via Digitalmars-d-learn]

On Friday, 19 March 2021 at 08:54:50 UTC, Paul Backus wrote:
On Friday, 19 March 2021 at 07:14:46 UTC, Jack wrote:
give below template struct, how can I list the members x, y 
and z? I've tried something with OriginalType and TemplateOf 
but no luck... it seems if I do foo!"str1" the "str1" became 
"part of type"? give .stringof from typeof(__traits(getMember, 
foo, field)) I thought the type would be foo!string or 
something.

You want std.traits.isInstanceOf:

    static if(!isType!m && isInstanceOf!(foo, typeof(m)))

thanks this works fine outside a method but not in a static 
method. what am I missing?

void main()
{
        // doesn't print anything
        Foo.list();
}

alias Foo = foo!();

template foo(string s = null)
{
        @nogc
        struct foo
        {
                int n;

                enum x = foo!"str1"(10);
                enum y = foo!"str2"(20);
                enum z = foo!"str3"(30);

                enum myEnum { none }

                void someMethod() { }

                static void list()
                {
                        //writeln("members = ", [__traits(allMembers, foo!())]);
                        static foreach(field; __traits(allMembers, foo!()))
                        {{
                                alias m = __traits(getMember, foo!(), field);
                                static if(!isType!m && isInstanceOf!(foo, 
typeof(m)))
                                {
                                        writefln("field = [%s]", field);
                                }
                        }}
                }
        }
}