Thoughts on versioning

[Ali Çehreli]

On 10/25/21 9:58 PM, zjh wrote:
> On Tuesday, 26 October 2021 at 01:19:29 UTC, Andrei Alexandrescu wrote:
>> Versioning Phobos would free us from maintaining backward
> 
> can we improve this
> ```d
> if (isInputRange!(Range1) && isInputRange!(Range2))
> ```
> to:
> ```d
> if isallInputRange(Range1,Range2)
> ```
> ?
> `C++`'s `concept` is very grace.
> 
> 

Easy in D but the following otherwise-attractive-short-hand-method 
imports symbols at module level (at least privately):

private import std.meta : allSatisfy;
private import std.range : isInputRange;

alias isallInputRange(T...) = allSatisfy!(isInputRange, T);

void foo(A, B)(A a, B b)
if (isallInputRange!(A, B)) {
}

unittest {
   static assert ( __traits(compiles, foo([0], [0])));
   static assert (!__traits(compiles, foo([0], 42)));
   static assert (!__traits(compiles, foo(42, [0])));
}

void main() {
}

Ali