So why double to float conversion is implicit ?

[aberba]

On Sunday, 22 October 2017 at 14:59:41 UTC, Andrei Alexandrescu 
wrote:
> On 10/22/17 9:41 AM, User wrote:
>> Is there a list of such quirks or gotchas in dlang?
>> 
>> The ones I know of are
>> 
>> 1. Implicit conversion from double to float
>> 
>> 2. Integer division results in integer result truncation the 
>> fractional part.
>
> These are not gotchas, as TDPL explains. One unpleasant related 
> gotcha is implicit conversions across signedness and comparison 
> of integral types with different signedness. -- Andrei

Shouldn't all these be documented?