https://issues.dlang.org/show_bug.cgi?id=13091
--- Comment #3 from bearophile_h...@eml.cc --- Thank you. Do you know the cause of this problem? void main() @safe { import std.algorithm: cartesianProduct; import std.array: array; const r = cartesianProduct([1], [1]).array; } test.d(4,41): Error: safe function 'D main' cannot call system function 'std.array.array!(Result).array' --