[Issue 17503] New: is-expression pattern in static if matches too many types

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=17503

          Issue ID: 17503
           Summary: is-expression pattern in static if matches too many
                    types
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: alex.bleron at gmail.com

In the following example, the static if branch is taken for both T=Vector!(int,
N) and T=Vector!(float, N), while it should only match Vector!(float,N)

-----------------------------------------------------

struct Vector(T, int N) 
{}

alias vec3 = Vector!(float, 3);
alias ivec3 = Vector!(int, 3);

struct Test(T)
{
  void test()
  {
    static if (is(T == Vector!(float, N), int N)) {
      pragma(msg, typeof(this).stringof, "..");
    }
  }
}

alias TestVec3 = Test!vec3;
alias TestIVec3 = Test!ivec3;

void main()
{
  TestVec3 tv3;
  TestIVec3 tiv3;
}

-----------------------------------------------------
Compiler output:

Test!(Vector!(float, 3))..
Test!(Vector!(int, 3))..

-----------------------------------------------------

Expected Compiler output:
Test!(Vector!(float, 3))..

-----------------------------------------------------
Link:
http://asm.dlang.org/#compilers:!((compiler:dmd2071,options:'',sourcez:FAZwLgTgrgxmAEA1ApnA9hAFAFQDTwEsA7BAOQEp5gBvAX2GAEMAbAxkeAN1QGZ4BeJKjAYAhJgBmzNIzD4e5ANxNW7Qtxh9BKdBHHE58BctCRYCbMnA5yNYPC5oCAE3hgrYTLYfV7D%2BOCyBDCEEvCYBCA4AtrCYpLSsvgU%2BAbwFJS%2B/v4ADhCMAOYAtoyYRSAF%2BGAAnjnIaBKYYAAWkeQAdOAQxAUN%2BABE7e39SlTZ9A709CpsHJbgOlrw82CiGjzKLLPLHgCSiwI74KIE6yacTq4lxF52DisHYJwbfiv7vG6nL7RAAAA%3D%3D)),filterAsm:(binary:!t),version:3

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