• German Diago (22/22) Feb 09 2018 Hello everyone,
• Boris-Barboris (15/17) Feb 09 2018 struct Outer
• Nicholas Wilson (5/32) Feb 09 2018 That looks like it should work. Perhaps you need to change
• German Diago (4/11) Feb 10 2018 Do not ask me why but now seems to work with my initial solution.

German Diago <germandiago gmail.com> writes:

Hello everyone,

I am trying to forward some member functions from a struct as a 
Catch-all function, so I did something like this:

     struct A {
         struct HeaderData {
           align(1):
           char [21] id;
           ubyte field1;
           ubyte field2;
         }

         Nullable!(HeaderData) headerData;


         auto opDispatch(string name)() {
           readHeader();
           static foreach (member; __traits(allMembers, 
HeaderData)) {
              static if (name == member) {
                  return mixin("headerData." ~ name);
              }
           }
       }

The mixin line does not work. I want to generate the access to 
the field. How could I achieve that?

Boris-Barboris <ismailsiege gmail.com> writes:

On Saturday, 10 February 2018 at 06:32:43 UTC, German Diago wrote:
 The mixin line does not work. I want to generate the access to 
 the field. How could I achieve that?


struct Outer
{
	struct Inner
	{
		int a;
		float b;
	}
	Inner i;
	
	auto opDispatch(string name)()
	{
		return __traits(getMember, i, name);
	}
}

Nicholas Wilson <iamthewilsonator hotmail.com> writes:

On Saturday, 10 February 2018 at 06:32:43 UTC, German Diago wrote:
 Hello everyone,

 I am trying to forward some member functions from a struct as a 
 Catch-all function, so I did something like this:

     struct A {
         struct HeaderData {
           align(1):
           char [21] id;
           ubyte field1;
           ubyte field2;
         }

         Nullable!(HeaderData) headerData;


         auto opDispatch(string name)() {
           readHeader();
           static foreach (member; __traits(allMembers, 
 HeaderData)) {
              static if (name == member) {
                  return mixin("headerData." ~ name);
              }
           }
       }

 The mixin line does not work. I want to generate the access to 
 the field. How could I achieve that?

That looks like it should work. Perhaps you need to change
`static if (name == member)` to
`static if (name == member.stringof)`

Alternatively you could do something like

     auto opDispatch(string name)() 
 if(hasMember!(HeaderData,name){
           readHeader();
           return mixin("headerData." ~ name);
     }

German Diago <germandiago gmail.com> writes:

On Saturday, 10 February 2018 at 07:47:58 UTC, Nicholas Wilson 
wrote:
 On Saturday, 10 February 2018 at 06:32:43 UTC, German Diago

 Alternatively you could do something like

     auto opDispatch(string name)() 
 if(hasMember!(HeaderData,name){
           readHeader();
           return mixin("headerData." ~ name);
     }


Do not ask me why but now seems to work with my initial solution. 
:)