https://issues.dlang.org/show_bug.cgi?id=12957

          Issue ID: 12957
           Summary: std.algorithm.cartesianProduct is sometimes very slow
                    to compile
           Product: D
           Version: D2
          Hardware: x86
                OS: Windows
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: Phobos
          Assignee: nobody@puremagic.com
          Reporter: bearophile_hugs@eml.cc

This program:

void main() {
    import std.algorithm: cartesianProduct;
    auto r3 = [0, 1, 2];
    foreach (x; cartesianProduct(r3, r3, r3, r3, r3, r3)) {}
}


On my PC gets compiled in about 9.4 seconds, using dmd 2.066alpha. In my opinion this is an excessive compilation time.

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