• Andrej Mitrovic (29/47) Aug 02 2012 So here's an implementation:

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

On 8/2/12, Andrej Mitrovic <andrej.mitrovich gmail.com> wrote:
 On 8/2/12, Walter Bright <newshound2 digitalmars.com> wrote:
 Known issue, it's an inevitable result (it never worked right anyway):

 http://d.puremagic.com/issues/show_bug.cgi?id=8454

 P.S. You might want to monitor the beta releases.

 I've posted about that exact Derelict case in Issue 3866 during the
 betas, but nobody replied.

 But a library solution could be made if one wants to use an inner
 alias. Maybe we even have one in Phobos? Something like:

 void foo(void delegate(string s, bool isTrue) dg)
 {
     alias DefVal!(dg, true) deg;
     // use deg as if it were dg() with default for 'isTrue'
 }

 Not the most readable code.. but it's similar to curry (except
 backwards) I guess.

So here's an implementation:

import std.stdio;
import std.traits;
import std.typetuple;

template DefVal(alias Call, DefVals...)
    if (isCallable!Call && DefVals.length <= ParameterTypeTuple!Call.length)
{
    auto DefVal(T...)(T args)
    {
        return Call(args, Reverse!DefVals);
    }
}

void foo(int x, float y, string z)
{
    writefln("x: %s, y: %s, z: %s", x, y, z);
}

void main()
{
    alias DefVal!(foo, "a", 1.0, 1) fooDef3;
    alias DefVal!(foo, "a", 1.0) fooDef2;
    alias DefVal!(foo, "a") fooDef1;
    alias DefVal!(foo) fooDef0;

    fooDef0(1, 1.0, "a");
    fooDef1(1, 1.0);
    fooDef2(1);
    fooDef3();
}

Essentially it's like the reverse of curry().