On Monday, 15 June 2015 at 03:53:35 UTC, Yuxuan Shui wrote:
Is it possible to apply some operation on every member of a
TypeTuple, then get the result back?
Say I have a TypeTuple of array types, and I want a TypeTuple
of their element types, how could I do that?
You can do that with std.typetuple.staticMap, example:
---
import std.stdio;
import std.typetuple;
template ElemType(T)
{
alias ElemType = typeof(T.init[0]);
}
void main(string[] args)
{
alias T1 = TypeTuple!(int[],ubyte[]);
alias T2 = staticMap!(ElemType, T1);
writeln(typeof(T1.init).stringof);
writeln(typeof(T2.init).stringof);
}
---
outputs:
---
(int[], ubyte[])
(int, ubyte)
---
It's like the higher-order function map() but for type list:
http://dlang.org/phobos/std_typetuple.html#.staticMap
