https://issues.dlang.org/show_bug.cgi?id=21510

          Issue ID: 21510
           Summary: __traits(isSame, a, AliasSeq!a) returns true if "a" is
                    a scalar
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Keywords: spec
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: maxsamukha@gmail.com

https://github.com/dlang/dmd/pull/11392 implies that the language designers decided not to flatten template argument tuples (or whatever is he right name) passed to __traits(isSame). The PR partially implements the decision but makes no distinction between a singleton tuple and a scalar, which introduces an undesirable inconsistency:

static assert(is(int == AliasSeq!int)); // false as expected
static assert(__traits(isSame, int, AliasSeq!int); // true, but false is
expected

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