• Andrei Alexandrescu (30/30) May 24 2020 /**
• Adam D. Ruppe (10/11) May 24 2020 Until semi-recently, you could not pass a built-in basic type to

Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:

/**
  * Returns an `AliasSeq` created from TList with the first occurrence
  * of type T, if found, replaced with type U.
  */
template Replace(T, U, TList...)
{
     alias Replace = GenericReplace!(T, U, TList).result;
}

/// Ditto
template Replace(alias T, U, TList...)
{
     alias Replace = GenericReplace!(T, U, TList).result;
}

/// Ditto
template Replace(T, alias U, TList...)
{
     alias Replace = GenericReplace!(T, U, TList).result;
}

/// Ditto
template Replace(alias T, alias U, TList...)
{
     alias Replace = GenericReplace!(T, U, TList).result;
}

Why all this? Delete it, rename GenericReplace to Replace, and call it a 
day.

I reckon documentation won't be as nice because GenericReplace just 
takes an ellipsis? Was this the rationale? I don't think it's much of a 
problem, and if we decide it is, version(StdDdoc) takes care of that 
with less aggravation.

This pattern is all over std.meta, and it's bad.

Adam D. Ruppe <destructionator gmail.com> writes:

On Monday, 25 May 2020 at 01:43:01 UTC, Andrei Alexandrescu wrote:
 Why all this?

Until semi-recently, you could not pass a built-in basic type to 
an `alias` param. I don't recall when that was changed, I think 
it last year, but surely the Phobos implementation predates that 
enhancement.

And you could use the ... before but that was perhaps too 
permissive. Or maybe the original author just didn't like that 
style.

But with alias accepting keyword types now, I imagine a LOT of 
phobos could be simplified to use it.