Re: Const Tuples

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On Friday, 25 April 2014 at 11:51:48 UTC, bearophile wrote:
They are not the same type:

void main() {
    import std.typecons: Tuple;
    alias T1 = const Tuple!(int, int);
    alias T2 = Tuple!(const int, const int);
    static assert(is(T1 == T2)); // Fails.
}


This type difference causes some troubles when you use tuples.

Bye,
bearophile

I think it's a bad idea to make these equal for this reason: if 
T1 == T2, then you would expect Unqual!T1 == Unqual!T2. However:

alias T1 = const Tuple!(int, int);
alias T2 = Tuple!(const int, const int);
assert(is(T1 == T2));

alias UnT1 = Unqual!T1; // Tuple!(int, int)
alias UnT2 = Unqual!T2; // Tuple!(const int, const int)
assert(is(UnT1 == UnT2));