newCTFE Status August 2019

[Jon Degenhardt]

On Thursday, 15 August 2019 at 21:42:47 UTC, Stefan Koch wrote:
> Hi Guys,
>
> I had 2 weeks of vacation recently, and I used them to work on 
> newCTFE again.
> [...]
>
> That said, I am hopeful to be able to release newCTFE in 2020!

Hi Stefan,

Great that you're still getting some time to work on this!

By coincidence, I just ran into a case. I'm curious, will newCTFE 
enable the usage below?

------------------
$ cat ctfe_case.d
struct C
{
     import std.conv : to;
     string s = double.init.to!string;   // Fails to compile.
}

void main()
{
     import std.stdio;
     C c;
     writeln(c.s);
}

$ dmd ctfe_case.d
/Library/D/dmd/src/phobos/std/exception.d(515): Error: uncaught 
CTFE exception std.format.FormatException("Cannot format floating 
point types at compile-time")
ctfe_case.d(4):        called from here: to(nan)
---------------

Using a similar code construct in a function works fine:

----------------
$ cat ctfe_case2.d
void main()
{
     import std.stdio;
     import std.conv : to;

     string s = double.init.to!string;
     writeln(s);
}
$ dmd ctfe_case2.d
$ ./ctfe_case2
nan
-----------------

--Jon