Bug 965 – `is(<uncompilable template>)` is true and doesn't gap errors if not in a function

This is a variation of issue #826 # class Templ(T){ # this(){ # unknown_identifier = 0; # } # } # # static assert(false == is(Templ!(int))); bug_e2ir_520_C.d(18): static assert (0 == 1) is false test case: http://dstress.kuehne.cn/compile/b/bug_e2ir_520_B.d

This is happening because compiling this()'s body is not necessary to determine the type. Not sure if this is a bug or not.

*** Issue 3416 has been marked as a duplicate of this issue. ***

This code compiles: --- struct S() { void f() { error; } } void f() { static assert(!is(S!())); // passes static if(is(S!())) { } // no errors } --- This bug is only for `is()` not in a function: --- struct S() { void f() { error; } } static assert(!is(S!())); // assertion fails static if(is(S!())) { } // Error: undefined identifier --- (In reply to comment #1) > This is happening because compiling this()'s body is not necessary to determine > the type. Not sure if this is a bug or not. This is a bug because an assertion passes in a function and because of "undefined identifier" error with `static if`. Someone familiar with dmd internals, mark bug 3448 as a duplicate or show the difference between `is(...)` and `__traits(compiles, ...)` in context of this issue.

*** Issue 5352 has been marked as a duplicate of this issue. ***

*** Issue 2167 has been marked as a duplicate of this issue. ***

All asserts in this issue pass under 2.075.1. Closing.