[your code here] Pure RPN calculator

[Iakh via Digitalmars-d]

On Wednesday, 26 July 2017 at 09:46:45 UTC, Timon Gehr wrote:
>>      readln.split.fold!((stack,op){
>>          switch(op){
>>              static foreach(c;"+-*/") case [c]:
>>                  return stack[0..$-2]~mixin("stack[$-2] "~c~" 
>> stack[$-1]");
>>              default: return stack~op.to!real;
>>          }
>>      })((real[]).init).writeln;

What does "case [c]:" mean?