How do you debug @safe @nogc code? Can't figure out how to print.

[Neia Neutuladh]

On Sat, 17 Nov 2018 21:16:13 +0000, aliak wrote:
> Could do. But it's not scalable. I'd have to comment out all the
> unittests that call the template function with a T that allocates inside
> the @nogc template (if I understood you correctly that it)

I meant something like:

    void debugln(T...)(T args) @nogc
    {
      import std.stdio;
      debug(MyProject) writeln(args);
    }

You use that function instead of writeln in your @nogc-compatible 
templates:

    void callFunc(alias func)()
    {
      debugln("about to call function!");
      func();
      debugln("done calling function!");
    }

Then I can write:

    @nogc:
    void foo() { printf("hello world\n"); }
    void main() { callFunc!foo(); }