User-defined template error messages

[Andrei Alexandrescu]

On 1/13/19 6:35 PM, Nicholas Wilson wrote:
> On Sunday, 13 January 2019 at 18:54:52 UTC, Andrei Alexandrescu wrote:
>> We've had this problem for a long time - template doesn't match 
>> because of a complex constraint, the error message is unhelpful, and 
>> the user doesn't know what to do.
>>
>> [...]
> 
> I've beat you to it: https://github.com/dlang/DIPs/pull/131 and I like 
> mine more. Syntactically it is compile-time contract programming, with 
> `in` replaced by `if`, easier to describe that way. See that PR thread 
> for more discussion.

Ah cool, that moves the discussion there. Thanks!