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

[Jack via Digitalmars-d-learn]

On Saturday, 20 March 2021 at 00:16:06 UTC, Steven Schveighoffer 
wrote:
On 3/19/21 12:41 PM, Jack wrote:
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)))

foo in this context is the *instantiated* foo (i.e. the struct 
foo above). What you want is `isIsntanceOf!(.foo, typeof(m))`

-Steve

Thank you Steve, that what I was looking for. Funny thing, I 
totally forget about the . operator