wrong "matches more than one template declaration" error with template specialization on alias parameters

[dlangBugzillaToGithub]

ag0aep6g reported this on 2016-08-18T22:40:29Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=16403

Description

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struct S(T) {}

/* This should work, but fails: */

enum fails(alias Tmpl, alias Inst : Tmpl!A, A) = true;
enum fails(alias Tmpl, alias Inst) = false;
static assert(fails!(S, S!int)); /* Error: template test.fails matches more than one template declaration */

/* These variations work: */

enum works1(alias Inst : S!A, A) = true;
enum works1(alias Inst) = false;
static assert(works1!(S!int)); /* passes */

enum works2(alias Tmpl, Inst : Tmpl!A, A) = true;
enum works2(alias Tmpl, Inst) = false;
static assert(works2!(S, S!int)); /* passes */
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