https://issues.dlang.org/show_bug.cgi?id=21917

          Issue ID: 21917
           Summary: Unused default values for IFTI parameters should not
                    be typechecked against the IFTI-inferred type
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P3
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: dlang-bugzilla@thecybershadow.net

This should work:

////////// test.d /////////
void fun(T)(T value = "hi")
{
}

void main()
{
    fun();        // OK
    fun("hello"); // OK
    fun(42);      // Error
}
///////////////////////////

The reason for why it should work is that e.g. we can't pass a range as a `fun` argument. A workaround is to declare an overload, but that doesn't scale well with the number of parameters.

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