• Francis Nixon (8/8) Jun 03 2017 When looking at std.variant I found the following line:
• Stefan Koch (4/12) Jun 03 2017 Those are positional arguments to format.
• Igor Shirkalin (2/10) Jun 03 2017 https://tour.dlang.org/tour/en/basics/alias-strings
• Basile B. (5/13) Jun 03 2017 - q{} is a string that cmust contains D tokens. They allow

Francis Nixon <13nixonf gmail.com> writes:

When looking at std.variant I found the following line:
return q{
     static if (allowed!%1$s && T.allowed!%1$s)
          if (convertsTo!%1$s && other.convertsTo!%1$s)
              return VariantN(get!%1$s %2$s other.get!%1$s);
}.format(tp, op);

I was wondering what exactly the % signs where doing/what they 
are for?

Stefan Koch <uplink.coder googlemail.com> writes:

On Saturday, 3 June 2017 at 16:22:33 UTC, Francis Nixon wrote:
 When looking at std.variant I found the following line:
 return q{
     static if (allowed!%1$s && T.allowed!%1$s)
          if (convertsTo!%1$s && other.convertsTo!%1$s)
              return VariantN(get!%1$s %2$s other.get!%1$s);
 }.format(tp, op);

 I was wondering what exactly the % signs where doing/what they 
 are for?

Those are positional arguments to format.
%1$s refers to the first argument (in this case tp)
while  %2$s refers to the second (op)

Igor Shirkalin <mathsoft inbox.ru> writes:

On Saturday, 3 June 2017 at 16:22:33 UTC, Francis Nixon wrote:
 When looking at std.variant I found the following line:
 return q{
     static if (allowed!%1$s && T.allowed!%1$s)
          if (convertsTo!%1$s && other.convertsTo!%1$s)
              return VariantN(get!%1$s %2$s other.get!%1$s);
 }.format(tp, op);

 I was wondering what exactly the % signs where doing/what they 
 are for?

https://tour.dlang.org/tour/en/basics/alias-strings

Basile B. <b2.temp gmx.com> writes:

On Saturday, 3 June 2017 at 16:22:33 UTC, Francis Nixon wrote:
 When looking at std.variant I found the following line:
 return q{
     static if (allowed!%1$s && T.allowed!%1$s)
          if (convertsTo!%1$s && other.convertsTo!%1$s)
              return VariantN(get!%1$s %2$s other.get!%1$s);
 }.format(tp, op);

 I was wondering what exactly the % signs where doing/what they 
 are for?

- q{} is a string that cmust contains D tokens. They allow 
highlightning in the editors, that's why you missed the point.

- % is a format specifier

- q{}.format() is format() called in the UFCS fashion