I have the following chunk of code that needs to conditionally
instantiate existing classes (at compilation time) named
classTickerCustom{ExchangeID} with one or ... two parameters (if
any); eg:
```d
/// securities trading on exchange primary currency; eg: USD
... = new classTickerCustomNYSE("AMC");
... = new classTickerCustomNASDAQ("TSLA");
/// securities trading on exchange secondary currency; eg: EUR
... = new classTickerCustomNYSE("XXX", "EUR");
... = new classTickerCustomNASDAQ("YYY", "EUR");
/// not real cases ... of course
```
And I already have a working solution using:
```d
static if (__traits(hasMember, "...", "...") == true) {
...
}
```
More specifically:
```d
...
mixin(format!
` /// code chunk
static if (__traits(hasMember, r"classTickerCustom%1$s"d,
r"lstrCurrencyID"d) == true) { /// checking whether target class
has an optional second parameter labeled lstrCurrencyID:
classTickerCustom%1$s lobjTickerCustom%1$s = new
classTickerCustom%1$s(
ludtTicker.symbolID,
ludtTicker.currencyID /// overriding exchange primary
currency ID with given one
);
} else {
classTickerCustom%1$s lobjTickerCustom%1$s = new
classTickerCustom%1$s(ludtTicker.symbolID);
}
`(sudtExchange.ID) /// code chunk
); /// mixin ending
...
```
However, __traits(hasMember, ...) checks for the existence of
anything labeled lstrCurrencyID within the class (eg: unrelated
variables with same name; not gonna happen, but, I like to code
it the right way); so, question is: is there any way to search
the parameter declarations only ?
Something akin to
https://dlang.org/spec/traits.html#getParameterStorageClasses but
for the parameter types/labels
