Let's say I have a class or an interface with a function, and I
want to pass that to a template to generate another function (in
this case one that passes it to a scripting engine, and allows it
to be called from there).
Currently I have the following issues:
1. I have to pass the class/interface type to the template, and I
cannot find anything about how to solve this issue.
2. It also doesn't work at the moment, as it wants to call the
member `Func` (name of the template argument) rather than the
Function described as such. (There's also probably in
std.functional I don't know about)
Code:
```d
extern (C) public int registerDDelegate(alias Func,
ClassType)(lua_State* state) nothrow
if(isSomeFunction!(Func)) {
import std.traits:Parameters, ReturnType;
Parameters!Func params;
int stackCounter = 0;
stackCounter--;
ClassType c = luaGetFromIndex!ClassType(state, stackCounter);
try {
foreach_reverse(ref param; params) {
stackCounter--;
param = luaGetFromIndex!(typeof(param))(state,
stackCounter);
}
} catch (Exception e) {
luaL_error(state, "Argument type mismatch with D functions!");
}
try {
static if(is(ReturnType!Func == void)) {
c.Func(params);
return 0;
} else static if(is(ReturnType!Func == struct)) {
auto retVal = c.Func(params);
static foreach (key ; retVal.tupleof) {
LuaVar(key).pushToLuaState(state);
}
return cast(int)retVal.tupleof.length;
} else {
LuaVar(c.Func(params)).pushToLuaState(state);
return 1;
}
} catch (Exception e) {
//luaPushVar(L, null);
lastLuaToDException = e;
try {
luaL_error(state, ("A D function threw:
"~e.toString~"!\0").ptr);
} catch(Exception e) {
luaL_error(state, "D threw when stringifying
exception!");
}
return 1;
}
}
```
