a function like writeln that returns a string rather than writes to a file

[Ali Çehreli]

On 5/1/20 7:40 PM, dan wrote:> On Saturday, 2 May 2020 at 02:29:43 UTC, 
H. S. Teoh wrote:
 >> On Sat, May 02, 2020 at 02:22:42AM +0000, dan via Digitalmars-d-learn
 >> wrote:
 >>> I'm looking for a function something like writeln or write, but
 >>> instead of writing to stdout, it writes to a string and returns the
 >>> string.
 >> [...]
 >>
 >>     import std.format : format;
 >>     string str = format("%s %s %s", obj1, obj2, obj3);
 >>
 >>
 >> T
 >
 > Thanks HS!
 >
 > That looks like a good move, if format will do the string conversion for
 > me.
 >
 > But one thing that would be troublesome is that i would have to make
 > sure to count up the %s so that they match the number of arguments.  I
 > would like to do without that, just like writeln does.

If you can live with a mildly awkward way of passing it, format() can 
take the format string at compile time as well:

   string str = format!"%s %s %s"(obj1, obj2, obj3);

You get a compilation error if format specifications don't match the 
arguments. (There are bug reports about that check but it mostly works 
great.)

Ali