Debug prints in @nogc

[Nordlöw via Digitalmars-d-learn]

On Tuesday, 30 August 2016 at 10:36:13 UTC, rikki cattermole 
wrote:
> On 30/08/2016 10:26 PM, Nordlöw wrote:
>> I'm struggling with debug printing in my @nogc-containers.
>>
>> The alternatives:
>>
>>     assert(false, "Fixed message with no parameters");
>>
>> is not enough for my needs
>>
>>     debug writeln("Fixed");
>>
>> doesn't bypass @nogc checking. Why?
>>
>> And temporary commenting out @nogc is cumbersome.
>>
>> I'm aware of C-style printf but that is not as flexible as 
>> writeln.
>>
>> Any advice?
>
> Static array + formattedWrite, perhaps?

I can't grasp how to use this from the docs at

https://dlang.org/library/std/format/formatted_write.html

uint fwrite(A...)(A a)
{
     import std.stdio : LockingTextWriter;
     import std.stdio : stdout;
     import std.format : formattedWrite;
     return formattedWrite!(stdout.lockingTextWriter)(a);
}

LockingTextWriter is not publicly exported from std.stdio and 
stdout.lockingTextWriter can not be read at compile-time.

Help please.