bug with CTFE std.array.array ?

[Timothee Cour]

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.