• frame (25/25) Dec 18 2020 The manual often doesn't show the full potential of traits on the

frame <frame86 live.com> writes:

The manual often doesn't show the full potential of traits on the 
first sight or what they are really good for. But there are also 
all-day scenarios where I would just be happy for a quick lookup.

For example, to assign a value to a class property which may have 
setter-overloads, I'm using a pattern like this:

void Foo(T, string property)(Variant data, T object) {
     static if(!isSomeFunction!(__traits(getMember, T, property))) 
{
         __traits(getMember, object, property) = 
data.get!(typeof(__traits(getMember, object, property)));
     } else {
         foreach(ov; __traits(getOverloads, T, property)) {
             static if((Parameters!ov).length == 1) {
                 __traits(getMember, object, property) = 
data.get!(Parameters!ov[0]);
             }
         }
     }
}

Somebody already may have a better implementation and of course 
it depends on your code - but it shows how to use it.

The part with the overloads is also important here because 
without it the compiler would complain about "functions cannot 
return function" or similiar errors and you would think 
__traits(getMember) could not handle that.