Idea: Introduce zero-terminated string specifier

[Jakob Ovrum]

On Wednesday, 3 October 2012 at 05:04:01 UTC, H. S. Teoh wrote:
> Yes that's what I mean. If the format string is known at 
> compile-time
> and known to involve only @safe code, then this would work. 
> Something
> like this might work if CTFE is used to parse the format string
> piecemeal (i.e., translate something like writefln("%d %s",x,y) 
> into
> write!int(x); write!string(" "); write!string(y)). The safe 
> instances of
> write!T(...) will be marked @safe.

It doesn't matter if the argument is known at compile-time or 
not, because there's no way to know that without receiving the 
format string as a template parameter, in which case it must 
*always* be known at compile-time (runtime format string would 
not be supported), and then the syntax is no longer writefln("%d 
%s", x, y). Obviously, such a change is not acceptable.

> I suppose we could just use @trusted
> and call it a day.

No, that would be abusing @trusted. The function would no longer 
be safe, *because it contains possibly unsafe code*. @trusted is 
for safe functions that the compiler cannot prove safe.