On Monday, 26 November 2012 at 18:20:39 UTC, Max Samukha wrote:
That is annoying. There *must* be a kind of single
unconstrained template parameter accepting anything that can be
an element of a "compile time" tuple. In other words, this must
work for any arguments without hassle:
template Foo(alias Head, Tail...)
{
alias TypeTuple!(Head, Tail) Foo;
}
As others said, you can workaround the deficiency with an
if-constraint, which is unsightly. FWIW, I have all my codebase
littered with "if (A.length == 1)" rubbish.
I agree, and if I remember previous discussions on the subject
correctly, it seems like only Walter is in favor of upholding the
current restrictions of "alias" parameters to symbols. I simply
do not see a point in pushing compiler implementation details on
the user like that – for the programmer, a type is a type is a
type…
Walter, do you have an example of a situation where the alias
parameter restriction would be beneficial? (for the D code
involved, I don't mean the few lines of code avoided in the
compiler)
David
