On Thursday, 21 May 2015 at 21:49:55 UTC, Freddy wrote:
std.traits has ImplicitConversionTargets.
Is there any template that returns the types that can implicty
convert to T?
You can write something like this:
---
import std.stdio;
import std.traits;
import std.typetuple;
void main(string[] args)
{
template PossibleType(From)
{
private alias All =
TypeTuple!(byte,ubyte,short,ushort,int,uint);
private alias Convertible(To) =
isImplicitlyConvertible!(From,To);
public alias PossibleType = Filter!(Convertible, All);
}
writeln((PossibleType!int).stringof);
writeln((PossibleType!short).stringof);
}
---
which outputs:
---
(int, uint)
(short, ushort, int, uint)
---
The idea is to reduce the list of all the possible types. It's
easy because the high-order functional functions are implemented
for the type list.
`All` could be a template parameter, and more filled, but to keep
the example simple here it's not.
