import std.array;

void main(){

  //enum a1=[1].array;//NG: Error: gc_malloc cannot be interpreted at compile time

  enum a2=" ".array;//OK

  import std.string;

  //enum a3=" ".splitLines.array;//NG

  enum a4="".splitLines.array;//OK

  enum a5=" ".split.array;//OK

  //enum a6=" a ".split.array;//NG

  import std.algorithm:filter;

  enum a7=" a ".split.filter!(a=>true).array;

  auto a8=" a ".split.array;

  assert(a8==a7);

  enum a9=[1].filter!(a=>true).array;//OK

}

I don't understand why the NG above fail (with Error: gc_malloc cannot be interpreted at compile time)

furthermore, it seems we can bypass the CT error with interleaving filter!(a=>true) (see above), which is even weirder.