When typeof(x)(...) is used as a struct literal, the compiler adds parentheses around typeof(x) in the generated .di file.  When the .di file is later used, the compiler interprets (typeof(x)) as a C-style cast.

I tend to use

   return typeof(return)(...);

a lot in generic code, and this issue makes header files completely unusable to me.


Test case:

$ cat test.d
struct S { int i; }
S foo() { return typeof(return)(123); }

$ dmd -c -o- -H test.d

$ cat test.di
// D import file generated from 'test.d'
struct S
{
    int i;
}
S foo()
{
return (typeof(return))(123);
}

$ dmd -c -o- test.di
test.di(8): C style cast illegal, use cast(typeof(return))123