Rory Mcguire wrote:
> Philippe Sigaud wrote:
>
>> On Fri, Aug 6, 2010 at 11:43, Rory Mcguire <rjmcgu...@gm_no_ail.com>
>> wrote:
>>
>>
>>> I've been trying to make a template for this but it seems that dmd still
>>> won't allow me to get the parameters of the constructors. dmd Seems to
>>> think
>>> that I'm trying to use it as a property.
>>>
>>>
>>
>>> void main() {
>>> foreach (m; __traits(getOverloads, A, "__ctor")) {
>>> pragma(msg, m.stringof); // it thinks I'm calling m
>>> }
>>> }
>>>
>>> constructors.d(34): Error: constructor constructors.A.this (int x) is
>>> not callable using argument types ()
>>>
>>
>> This is my new once-a-day bug :(
>> Using a function alias, and being unable to call properties on it,
>> because DMD thinks I'm calling it. Man, it's no property, just a name!
>>
>> Anyway, just pragma(msg, m) works, strangely.
>> I think I found a way to use m, somewhat:
>>
>> void main() {
>> foreach (m; __traits(getOverloads, A, "__ctor")) {
>> pragma(msg, m); // it thinks I'm calling m
>> typeof(&m) tmp = &m;
>> writeln( (ParameterTypeTuple!tmp).stringof); // (int), (double),
>> (string)
>> writeln( (ParameterTypeTuple!m).stringof); // (int), (int), (int)
>> writeln( typeof(&m).stringof); // A function(int x), A
>> function(double x), A function(string s)
>> }
>> }
>>
>> using ParameterTypeTuple!m directly does not differentiate the m's. But
>> using a temporary pointer, it seems to work.
>>
>> Oh and I even get the arguments names !
>>
>>
>> Philippe
>
> Thanks!! works now. Now we just need to be able to select which
> constructors we actually want.
>
> string inheritconstructors_helper(alias T)() {
> string s;
> foreach (m; __traits(getOverloads, T, "__ctor")) {
> string args, args1;
> foreach (i, cons; ParameterTypeTuple!(typeof(&m))) {
> pragma(msg, cons.stringof);
> args ~= ","~cons.stringof~" v"~to!string(i);
> args1 ~= ",v"~to!string(i);
> }
> args = args.length < 1 ? args : args[1..$];
> args1 = args1.length < 1 ? args1 : args1[1..$];
> s ~= "this("~args~") { super("~args1~"); }\n";
> }
> return s;
> }
>
> class A {
> int i;
> //private this() {}
> this(int x) {
> i = x;
> }
> this(float x) {
> i = cast(int)x; // ignore bad code
> }
> this(string s, int mul) { // test multiple args
> i = to!int(s) * mul;
> }
> }
> class B : A {
> mixin(inheritconstructors_helper!A());
> // InheritConstructors!A;
> }
>
>
>
> void main() {
> A a = new B(4);
> a = new B("42", 2);
> }
Got selection working:
string inheritconstructors_helper(alias T,Selectors...)() {
string s;
foreach (m; __traits(getOverloads, T, "__ctor")) {
string args, args1;
pragma(msg, typeof(&m));
/*foreach (sel; Selectors) {
pragma(msg, sel, is (sel == typeof(&m)));
continue top;
}*/
if (staticIndexOf!(typeof(&m), Selectors)==-1) {
continue;
}
foreach (i, cons; ParameterTypeTuple!(typeof(&m))) {
pragma(msg, cons.stringof);
args ~= ","~cons.stringof~" v"~to!string(i);
args1 ~= ",v"~to!string(i);
}
args = args.length < 1 ? args : args[1..$];
args1 = args1.length < 1 ? args1 : args1[1..$];
s ~= "this("~args~") { super("~args1~"); }\n";
}
return s;
}
Usage:
class B : A {
mixin(inheritconstructors_helper!(A,TypeTuple!(A function(string,int)
,A function(int)))());
}
