Ary Borenszweig wrote:
Don wrote:
I'm trying to make sense of the rules for 'typeof'. It's difficult
because DMD's behaviour is so different to the spec. Here's four
simple cases.
// This doesn't compile on D1.
//alias typeof(int*int) Alias1;
Not valid: typeof accepts an expression and "int*int" is not a valid
expression.
Agreed.
// This compiles in D1, but not in D2.
alias int Int;
alias typeof(Int*Int) Alias2;
Almost same as above: Int resolves to a type and "type*type" is not a
valid expression.
Agreed.
// Yet this DOES compile on D2 !
typeof(T*U) foo(T, U)(T x, U y) { return x*y; }
alias typeof(foo(Int, Int)) Alias3;
Of course, because this doesn't translate to "Int*Int", this translates
to some variables x and y of type "Int" and "Int" respectively for which
you can do "x*y".
How does it get from Int to an instance of type Int?
The first issue is typeof( T * U ). T and U are not variables, they are
types.
