I think the need to put const values inside tuples is very common:


import std.typecons;
void main() {
    const int x = 1;
    auto t1 = tuple(x);
    alias Tuple!(const(int)) T;
    auto t2 = T(1);
}


In DMD 2.054beta this gives:

...\dmd\src\phobos\std\typecons.d(666): Error: can only initialize const member _field_field_0 inside constructor
test.d(4): Error: template instance std.typecons.tuple!(const(int)) error instantiating