Re: Debug prints in @nogc

[rikki cattermole via Digitalmars-d-learn]

On 30/08/2016 11:10 PM, Nordlöw wrote:

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.

I fixed your code but lockingTextWriter is not @nogc.

void main() @nogc {
     import std.stdio : stdout;
     import std.format : formattedWrite;
     formattedWrite(stdout.lockingTextWriter, "%x", 7);
}

Okay looks like formattedWrite isn't @nogc able. Oh wells thought it was.
Please create an issue as this is quite an important feature.