On Tuesday, 21 August 2018 at 08:08:58 UTC, Andrey wrote:
Hello,
I have a function:
string format(string pattern, T...)(T value)
{
auto writer = appender!string();
writer.formattedWrite!pattern(convertToUnderlyingType(value));
//Tuple!T(value).expand.to!(OriginalType!T)
return writer.data;
}
The "value" in this function can be any type including "enum".
And if it is a "enum" I want to print it's contents not name.
So what I need - check if current argument in template pack is
enum then convert it in original type. If current argument
isn't enum - leave it as is. In my example I showed it with
imaginary function "convertToUnderlyingType".
How to implement it in D?
Do you mean something like this:
´´´
import std.stdio;
import std.traits;
import std.range;
import std.format;
import std.meta;
enum E
{
A = "a",
B = "b"
}
void main()
{
format!"%s"("kuku").writeln;
format!"%s"(E.A).writeln;
format!"%s %s"("kuku", E.A).writeln;
}
string format(string pattern, T...)(T vals)
{
auto writer = appender!string();
writer.formattedWrite!pattern(convertToUnderlyingType!(vals));
//Tuple!T(value).expand.to!(OriginalType!T)
return writer.data;
}
template convertToUnderlyingType(T...)
{
alias convertToUnderlyingType =
staticMap!(convertToUnderlyingTypeSingle, T);
}
auto convertToUnderlyingTypeSingle(alias value)()
{
static if(is(typeof(value) == enum))
{
return cast(OriginalType!(typeof(value)))value;
}
else
{
return value;
}
}
´´´
