@trust is an encapsulation method, not an escape

[Walter Bright via Digitalmars-d]

On 2/5/2015 9:00 PM, "Ola Fosheim =?UTF-8?B?R3LDuHN0YWQi?= 
<ola.fosheim.grostad+dlang at gmail.com>" wrote:
> On Thursday, 5 February 2015 at 23:39:39 UTC, Walter Bright wrote:
>>   static void trustedMemcopy(T[] dest, T[] src) @trusted
>>   {
>>     assert(src.length == dest.length);
>>     memcpy(dest.ptr, src.ptr, src.length * T.sizeof);
>>   }
>>
>> I don't have to review callers of trustedMemory() because it encapsulates an
>> unsafe operation (memcpy) with a safe interface.
>
> It might have done so if it ensured that T was a proper value type, but
> unfortunately D's type system is not strong enough.
>
> What happens if T is a unique_ptr style reference? Ouch, two unique references
> to the same object. Ouch, memory unsafe.

Good point. Then a constraint can be added to the function signature that T is 
copyable.

D's type system is strong enough for that.