Re: how to get UDA only for methods

[Stanislav Blinov via Digitalmars-d-learn]

On Wednesday, 17 October 2018 at 02:54:26 UTC, test wrote:
I need get the Route UDA only for method without (static 
methods, property, constructor, destructor), dont know how to 
do it.

1) Note that __traits(allMembers, T) gets you a tuple of names, 
not actual member aliases.
2) Remember there may be overloads
3) Filter the unwanted out:

import std.traits;
import std.meta : Alias, AliasSeq;
import std.stdio;
import std.string : startsWith;
import std.algorithm : among;

alias operatorNames = AliasSeq!("opUnary", "opIndexUnary", 
"opCast", "opBinary", "opBinaryRight",
                                "opIn", "opIn_r", "opEquals", 
"opCmp", "opCall", "opAssign",
                                "opIndexAssign", "opOpAssign", 
"opIndexOpAssign", "opSliceOpAssign",
                                "opIndex", "opSlice", "opDollar", 
"opDispatch");

void main() {
    writeln(getRoutes!App);
}

struct Route { string r; }

Route[] getRoutes(T)(){
    Route[] routes;
    foreach (name; __traits(allMembers, T)) {
        alias member = Alias!(__traits(getMember, T, name));
        static if (__traits(isStaticFunction, member) ||
                   name.startsWith("__")              ||
                   name.among(operatorNames))
        {}
        else static if (is(typeof(member) == function)) {
            foreach (overload; __traits(getOverloads, T, name)) {
                pragma(msg, name);
                static foreach(route; getUDAs!(overload, Route)) {
                    routes  ~= route;
                }
            }
        }
    }
    return routes;
}

struct App {

    @Route("xxx")
    int field;

    @Route("/blah")
    this(this) {}

    @Route("ggg")
    ~this() {}

    @Route("/index")
    void home() {}

    @Route("/index2")
    void home(bool overloaded) {}

    @Route("/blog")
    void blog(){}
}